diff --git a/app/benchmark_fft/main.cpp b/app/benchmark_fft/main.cpp
index 73c9a1f..0a34b30 100644
--- a/app/benchmark_fft/main.cpp
+++ b/app/benchmark_fft/main.cpp
@@ -37,7 +37,7 @@ void conquer(fft::complex_vector::iterator data, int n) {
 
 constexpr int MAX_NUM_THREADS = 8;
 constexpr int MAX_NUM_TASKS = 32;
-constexpr int MAX_STACK_SIZE = 1024 * 1;
+constexpr int MAX_STACK_SIZE = 1024 * 4;
 
 static_scheduler_memory<MAX_NUM_THREADS,
                         MAX_NUM_TASKS,
diff --git a/app/benchmark_fib/main.cpp b/app/benchmark_fib/main.cpp
index e9bf411..a4c2a99 100644
--- a/app/benchmark_fib/main.cpp
+++ b/app/benchmark_fib/main.cpp
@@ -33,7 +33,7 @@ int pls_fib(int n) {
 
 constexpr int MAX_NUM_THREADS = 8;
 constexpr int MAX_NUM_TASKS = 32;
-constexpr int MAX_STACK_SIZE = 1024 * 1;
+constexpr int MAX_STACK_SIZE = 1024 * 64;
 
 static_scheduler_memory<MAX_NUM_THREADS,
                         MAX_NUM_TASKS,
@@ -51,6 +51,7 @@ int main(int argc, char **argv) {
   scheduler scheduler{global_scheduler_memory, (unsigned) num_threads};
 
   volatile int res;
+
   scheduler.perform_work([&]() {
     for (int i = 0; i < fib::NUM_WARMUP_ITERATIONS; i++) {
       res = pls_fib(fib::INPUT_N);
diff --git a/app/playground/main.cpp b/app/playground/main.cpp
index 7dc5d0c..74bfe91 100644
--- a/app/playground/main.cpp
+++ b/app/playground/main.cpp
@@ -6,34 +6,21 @@ using namespace context_switcher;
 using namespace std;
 
 // Memory for custom stack and continuation semantics
-const size_t STACK_SIZE = 512 * 16;
+const size_t STACK_SIZE = 512 * 32;
 const size_t NUM_STACKS = 4;
 char custom_stacks[NUM_STACKS][STACK_SIZE];
 
 volatile int result;
 
 int main() {
-  context_switcher::continuation outer_cont = enter_context(custom_stacks[0], STACK_SIZE, [](continuation &&main_cont) {
-    enter_context(custom_stacks[1], STACK_SIZE, [&main_cont](continuation &&middle_cont) {
-      enter_context(custom_stacks[2], STACK_SIZE, [&main_cont](continuation &&inner_cont) {
-        for (int i = 0; i < 10; i++) {
-          printf("Inner %d\n", i);
-          main_cont = context_switcher::switch_context(std::move(main_cont));
-        }
-
-        return std::move(inner_cont);
-      });
-
-      return std::move(middle_cont);
+  while (true) {
+    context_switcher::continuation cont = enter_context(custom_stacks[0], STACK_SIZE, [](continuation &&main_cont) {
+//      main_cont = context_switcher::switch_context(std::move(main_cont));
+      return std::move(main_cont);
     });
 
-    return std::move(main_cont);
-  });
-
-  for (int i = 0; i < 10; i++) {
-    printf("Outer %d\n", i);
-    outer_cont = context_switcher::switch_context(std::move(outer_cont));
-  }
+//    cont = context_switcher::switch_context(std::move(cont));
+  };
 
   return 0;
 }
diff --git a/cmake/SetupThreadSanitizer.cmake b/cmake/SetupThreadSanitizer.cmake
index 9d9cc92..d1135b7 100644
--- a/cmake/SetupThreadSanitizer.cmake
+++ b/cmake/SetupThreadSanitizer.cmake
@@ -6,5 +6,7 @@ option(THREAD_SANITIZER "Add thread sanitizer" OFF)
 if (THREAD_SANITIZER)
     add_compile_options(-fsanitize=thread -g -fno-omit-frame-pointer)
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=thread -fno-omit-frame-pointer")
+
+    add_compile_definitions(THREAD_SANITIZER)
 endif ()
 message("-- Thread Sanitizer: ${THREAD_SANITIZER}")
diff --git a/lib/context_switcher/CMakeLists.txt b/lib/context_switcher/CMakeLists.txt
index 0b4ef63..eebcf0f 100644
--- a/lib/context_switcher/CMakeLists.txt
+++ b/lib/context_switcher/CMakeLists.txt
@@ -7,23 +7,54 @@ project(context_switcher
 set(CMAKE_CXX_STANDARD 11)
 
 # Platform Support - Edit this when porting the context switch facility.
-# We are rather conservative with our flags, maybe more systems follow implemented calling conventions.
-# See our documentation and boost context for help when adding a new system.
-if (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND CMAKE_SYSTEM_NAME STREQUAL "Linux")
-    SET(CONTEXT_SWITCH_ASSEMBLY "asm/enter_context_x86_64.s" "asm/switch_context_x86_64.s")
-elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL "armv7l" AND CMAKE_SYSTEM_NAME STREQUAL "Linux")
-    SET(CONTEXT_SWITCH_ASSEMBLY "asm/enter_context_arm32.s" "asm/switch_context_arm32.s")
+# Settings:
+# CS_USE_BOOST              = ON/OFF        Use boost's fcontext as the assembly implementation for the context switch.
+# CS_USE_FAST               = ON/OFF        Use custom implementation optimized for fast creation/return context switch.
+# CMAKE_SYSTEM_PROCESSOR    = String        Target processor
+# CMAKE_SYSTEM_NAME         = String        Target
+#
+# Typically cross compiling in cmake will set CMAKE_SYSTEM_PROCESSOR and CMAKE_SYSTEM_NAME.
+# The library uses these two to select the correct assembly file for performing the context switch.
+# We currently only include minimal system support in our config file. The fastest way to port the
+# library is to see if one of the boost.context assembly files matches your target platform and adding
+# that to tho selection script.
+#
+# By default we use CS_USE_FAST if available and fall back to CS_USE_BOOST if needed.
+# When sanitizers are turned on (or other instrumentation) we recommend to use CS_USE_BOOST
+# as its calling convention causes no problems with function entry/exit instrumentation.
+
+message("-- Configure Context Switcher: ${CMAKE_SYSTEM_PROCESSOR} running ${CMAKE_SYSTEM_NAME}")
+include(asm/cscontext/SelectAssemblyFiles.cmake)
+include(asm/fcontext/SelectAssemblyFiles.cmake)
+
+if (CS_CSCONTEXT_FOUND AND NOT THREAD_SANITIZER AND NOT CS_FORCE_FALLBACK)
+    MESSAGE("-- Using cscontext implementation")
+    SET(CS_CONTEXT_SWITCH_ASSEMBLY ${CS_CSCONTEXT_ASSEMBLY})
+    SET(CS_USE_CSCONTEXT TRUE)
+elseif (CS_FCONTEXT_FOUND)
+    if (THREAD_SANITIZER)
+        MESSAGE("-- Falling back to fcontext implementation (thread sanitizer active)")
+    else ()
+        MESSAGE("-- Falling back to fcontext implementation")
+    endif ()
+    SET(CS_CONTEXT_SWITCH_ASSEMBLY ${CS_FCONTEXT_ASSEMBLY})
+    SET(CS_USE_CSCONTEXT FALSE)
 else ()
     MESSAGE(FATAL_ERROR "Platform (${CMAKE_SYSTEM_PROCESSOR} on ${CMAKE_SYSTEM_NAME}) not supported! Please see Readme for instructions to port.")
 endif ()
-message("-- Context Switcher: ${CMAKE_SYSTEM_PROCESSOR} running ${CMAKE_SYSTEM_NAME}")
+message("-- Configure Context Switcher: Configuration Done")
 
 add_library(context_switcher STATIC
-        ${CONTEXT_SWITCH_ASSEMBLY}
+        ${CS_CONTEXT_SWITCH_ASSEMBLY}
         include/context_switcher/context_switcher.h src/context_switcher.cpp
-        include/context_switcher/assembly_bindings.h
+        include/context_switcher/cscontext.h
+        include/context_switcher/fcontext.h
         include/context_switcher/continuation.h
-        include/context_switcher/lambda_capture.h)
+        include/context_switcher/lambda_capture.h include/context_switcher/context.h)
+
+if (CS_USE_CSCONTEXT)
+    target_compile_definitions(context_switcher PUBLIC CS_USE_CSCONTEXT)
+endif ()
 
 # Add everything in `./include` to be in the include path of this project
 target_include_directories(context_switcher
diff --git a/lib/context_switcher/asm/cscontext/SelectAssemblyFiles.cmake b/lib/context_switcher/asm/cscontext/SelectAssemblyFiles.cmake
new file mode 100644
index 0000000..9777b97
--- /dev/null
+++ b/lib/context_switcher/asm/cscontext/SelectAssemblyFiles.cmake
@@ -0,0 +1,20 @@
+# Tries to locate the correct CS_FAST_ASSEMBLY files for this platform and
+# sets CS_CSCONTEXT_FOUND to true if the platform is supported.
+#
+# To add a platform add a clause locating the correct assembly implementations for the system.
+
+SET(CS_CSCONTEXT_FOUND TRUE)
+if (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    # Typical Linux running on x86_64
+    SET(CS_CSCONTEXT_ASSEMBLY
+            asm/cscontext/enter_context_x86_64_sysv_elf.s
+            asm/cscontext/switch_context_x86_64_sysv_elf.s)
+else ()
+    SET(CS_CSCONTEXT_FOUND FALSE)
+endif ()
+
+if (CS_CSCONTEXT_FOUND)
+    MESSAGE("-- CS_CSCONTEXT_FOUND: ${CS_CSCONTEXT_ASSEMBLY}")
+else ()
+    MESSAGE("-- CS_CSCONTEXT_FOUND: NOT FOUND")
+endif ()
diff --git a/lib/context_switcher/asm/enter_context_x86_64.s b/lib/context_switcher/asm/cscontext/enter_context_x86_64_sysv_elf.s
similarity index 81%
rename from lib/context_switcher/asm/enter_context_x86_64.s
rename to lib/context_switcher/asm/cscontext/enter_context_x86_64_sysv_elf.s
index 44b29d3..d76704a 100644
--- a/lib/context_switcher/asm/enter_context_x86_64.s
+++ b/lib/context_switcher/asm/cscontext/enter_context_x86_64_sysv_elf.s
@@ -17,11 +17,9 @@ __cs_enter_context:
         # Variables
         # r12 = temporary for the old stack pointer
 
-        pushq %rbp
-        movq %rsp, %rbp
-        subq $0x38, %rsp
-
         ############### Save State ###############
+        # Make space on the stack
+        leaq -0x38(%rsp), %rsp
         # Store calee saved general registers.
         movq %r12, 0x00(%rsp)
         movq %r13, 0x08(%rsp)
@@ -43,12 +41,13 @@ __cs_enter_context:
         # Switch to new stack pointer.
         movq %rdi, %rsp
 
-        # Init the new stack (in our case we want the stack trace to 'stick' to where it was created.
-        # This will not necessary be valid all the time (thus returning into it is not ok), but
-        # we only use it for debugging as we explicitly state throwing exceptions beyond the fiber is not ok.
-        # pushq 0x8(%rbp)
-        # pushq 0x0(%rbp)
-        # movq %rsp, %rbp
+        # Init the new stack to something reasonable.
+        # Here we point it at the finish part of our function with the frame pointer at 0x0.
+        # This is not stricly required, but stops debuggers/tools from freaking out.
+        leaq  __cs_finish(%rip), %r13
+        pushq %r13
+        pushq $0x0
+        movq %rsp, %rbp
 
         # Perform actual function call, this will now be on the new stack
         # rdi = first parametor to callback (continuation)
@@ -73,12 +72,18 @@ __cs_enter_context:
         ldmxcsr 0x30(%rsp)
         # restore x87 control-word
         fldcw 0x34(%rsp)
+        # Free space on the stack
+        leaq 0x38(%rsp), %rsp
         ############ Restore State  ############
 
         # Just return back from the call.
         # This is the end of a fiber, so we have no continuation.
         xor %rax, %rax
-
-        movq %rbp, %rsp
-        popq %rbp
         ret
+
+__cs_finish:
+        # exit code is zero
+        xorq  %rdi, %rdi
+        # exit application
+        call  _exit@PLT
+        hlt
diff --git a/lib/context_switcher/asm/switch_context_x86_64.s b/lib/context_switcher/asm/cscontext/switch_context_x86_64_sysv_elf.s
similarity index 91%
rename from lib/context_switcher/asm/switch_context_x86_64.s
rename to lib/context_switcher/asm/cscontext/switch_context_x86_64_sysv_elf.s
index bb4d9ab..47af59e 100644
--- a/lib/context_switcher/asm/switch_context_x86_64.s
+++ b/lib/context_switcher/asm/cscontext/switch_context_x86_64_sysv_elf.s
@@ -11,11 +11,9 @@ __cs_switch_context:
         # Return
         # rax = continuation that returned control back to the caller (null if fallthrough)
 
-        pushq %rbp
-        movq %rsp, %rbp
-        subq $0x38, %rsp
-
         ############### Save State ###############
+        # Make space on the stack
+        leaq -0x38(%rsp), %rsp
         # Store calee saved general registers.
         movq %r12, 0x00(%rsp)
         movq %r13, 0x08(%rsp)
@@ -47,10 +45,10 @@ __cs_switch_context:
         ldmxcsr 0x30(%rsp)
         # restore x87 control-word
         fldcw 0x34(%rsp)
+        # Free space on the stack
+        leaq 0x38(%rsp), %rsp
         ############ Restore State  ############
 
         # Return the context we came from as a continuation.
         # rax has already the correct value
-        movq %rbp, %rsp
-        popq %rbp
         ret
diff --git a/lib/context_switcher/asm/enter_context_arm32.s b/lib/context_switcher/asm/enter_context_arm32.s
deleted file mode 100644
index 953531b..0000000
--- a/lib/context_switcher/asm/enter_context_arm32.s
+++ /dev/null
@@ -1,53 +0,0 @@
-	.arm
-	.text
-	.global	__cs_enter_context
-	.type	__cs_enter_context, %function
-
-__cs_enter_context:
-        /* Parameter List (in order)
-        * r0 = new stack pointer
-        * r1 = first parameter to callback
-        * r2 = callback function pointer
-        * r3 = new stack limit (not used on most platforms)
-        *
-        * Return
-        * r0 = continuation that returned control back to the caller (null if fallthrough)
-        *
-        * Variables
-        * r4 = temporary for the old stack pointer */
-
-        /* ========== Save State ========== */
-        /* store programm counter for later return */
-        push {lr}
-        /* store callee saved registers */
-        push {r4-r12,lr}
-        /* ========== Save State ========== */
-
-        /* Perform change to new stack */
-        /* Keep old stack as second parameter to our callback function. */
-        mov r4, sp
-        /* Make sure that stack start is properly aligned. */
-        and r0, r0, #-16
-        /* Switch to new stack pointer. */
-        mov sp, r0
-
-        /* Perform actual function call, this will now be on the new stack */
-        /* r0 = first parametor to callback (continuation) */
-        /* r1 = second parameter to callback (arbetary pointer) */
-        mov r0, r4
-        blx r2
-
-        /* Restore state of returned continuation. */
-        /* To do so we first reset the stack pointer (which we get returned in r0). */
-        /* After that we execute our standard restore procedere to pop the state from the stack. */
-        mov sp, r0
-
-        /* ========== Restore State ========== */
-        /* restore callee saved registers */
-        pop {r4-r12,lr}
-        /* ========== Restore State ========== */
-
-        /* Just return back from the call. */
-        /* This is the end of a fiber, so we have no continuation. */
-        eor r0, r0, r0
-        pop {pc}
diff --git a/lib/context_switcher/asm/fcontext/SelectAssemblyFiles.cmake b/lib/context_switcher/asm/fcontext/SelectAssemblyFiles.cmake
new file mode 100644
index 0000000..25d91fe
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/SelectAssemblyFiles.cmake
@@ -0,0 +1,27 @@
+# Tries to locate the correct CS_FCONTEXT_ASSEMBLY files for this platform and
+# sets CS_FCONTEXT_FOUND to true if the platform is supported.
+#
+# To add a platform add a clause locating the correct assembly implementations for the system.
+
+SET(CS_FCONTEXT_FOUND TRUE)
+if (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    # Typical Linux running on x86_64
+    SET(CS_FCONTEXT_ASSEMBLY
+            asm/fcontext/jump_x86_64_sysv_elf_gas.S
+            asm/fcontext/make_x86_64_sysv_elf_gas.S
+            asm/fcontext/ontop_x86_64_sysv_elf_gas.S)
+elseif (CMAKE_SYSTEM_PROCESSOR STREQUAL "armv7l" AND CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    # Typical Linux running on ARMv7
+    SET(CS_FCONTEXT_ASSEMBLY
+            asm/fcontext/jump_arm_aapcs_elf_gas.S
+            asm/fcontext/make_arm_aapcs_elf_gas.S
+            asm/fcontext/ontop_arm_aapcs_elf_gas.S)
+else ()
+    SET(CS_FCONTEXT_FOUND FALSE)
+endif ()
+
+if (CS_FCONTEXT_FOUND)
+    MESSAGE("-- CS_FCONTEXT_FOUND: ${CS_FCONTEXT_ASSEMBLY}")
+else ()
+    MESSAGE("-- CS_FCONTEXT_FOUND: NOT FOUND")
+endif ()
diff --git a/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_elf_gas.S
new file mode 100644
index 0000000..cefd183
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_elf_gas.S
@@ -0,0 +1,114 @@
+/*
+       Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "jump_arm64_aapcs_elf_gas.S"
+.text
+.align  2
+.global jump_fcontext
+.type   jump_fcontext, %function
+jump_fcontext:
+    # prepare stack for GP + FPU
+    sub  sp, sp, #0xb0
+
+    # save d8 - d15
+    stp  d8,  d9,  [sp, #0x00]
+    stp  d10, d11, [sp, #0x10]
+    stp  d12, d13, [sp, #0x20]
+    stp  d14, d15, [sp, #0x30]
+
+    # save x19-x30
+    stp  x19, x20, [sp, #0x40]
+    stp  x21, x22, [sp, #0x50]
+    stp  x23, x24, [sp, #0x60]
+    stp  x25, x26, [sp, #0x70]
+    stp  x27, x28, [sp, #0x80]
+    stp  x29, x30, [sp, #0x90]
+
+    # save LR as PC
+    str  x30, [sp, #0xa0]
+
+    # store RSP (pointing to context-data) in X0
+    mov  x4, sp
+
+    # restore RSP (pointing to context-data) from X1
+    mov  sp, x0
+
+    # load d8 - d15
+    ldp  d8,  d9,  [sp, #0x00]
+    ldp  d10, d11, [sp, #0x10]
+    ldp  d12, d13, [sp, #0x20]
+    ldp  d14, d15, [sp, #0x30]
+
+    # load x19-x30
+    ldp  x19, x20, [sp, #0x40]
+    ldp  x21, x22, [sp, #0x50]
+    ldp  x23, x24, [sp, #0x60]
+    ldp  x25, x26, [sp, #0x70]
+    ldp  x27, x28, [sp, #0x80]
+    ldp  x29, x30, [sp, #0x90]
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # X0 == FCTX, X1 == DATA
+    mov x0, x4
+
+    # load pc
+    ldr  x4, [sp, #0xa0]
+
+    # restore stack from GP + FPU
+    add  sp, sp, #0xb0
+
+    ret x4
+.size   jump_fcontext,.-jump_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_macho_gas.S
new file mode 100644
index 0000000..31738f7
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_arm64_aapcs_macho_gas.S
@@ -0,0 +1,109 @@
+/*
+         Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _jump_fcontext
+.balign 16
+_jump_fcontext:
+    ; prepare stack for GP + FPU
+    sub  sp, sp, #0xb0
+
+    ; save d8 - d15
+    stp  d8,  d9,  [sp, #0x00]
+    stp  d10, d11, [sp, #0x10]
+    stp  d12, d13, [sp, #0x20]
+    stp  d14, d15, [sp, #0x30]
+
+    ; save x19-x30
+    stp  x19, x20, [sp, #0x40]
+    stp  x21, x22, [sp, #0x50]
+    stp  x23, x24, [sp, #0x60]
+    stp  x25, x26, [sp, #0x70]
+    stp  x27, x28, [sp, #0x80]
+    stp  fp,  lr,  [sp, #0x90]
+
+    ; save LR as PC
+    str  lr, [sp, #0xa0]
+
+    ; store RSP (pointing to context-data) in X0
+    mov  x4, sp
+
+    ; restore RSP (pointing to context-data) from X1
+    mov  sp, x0
+
+    ; load d8 - d15
+    ldp  d8,  d9,  [sp, #0x00]
+    ldp  d10, d11, [sp, #0x10]
+    ldp  d12, d13, [sp, #0x20]
+    ldp  d14, d15, [sp, #0x30]
+
+    ; load x19-x30
+    ldp  x19, x20, [sp, #0x40]
+    ldp  x21, x22, [sp, #0x50]
+    ldp  x23, x24, [sp, #0x60]
+    ldp  x25, x26, [sp, #0x70]
+    ldp  x27, x28, [sp, #0x80]
+    ldp  fp,  lr,  [sp, #0x90]
+
+    ; return transfer_t from jump
+    ; pass transfer_t as first arg in context function
+    ; X0 == FCTX, X1 == DATA
+    mov x0, x4
+
+    ; load pc
+    ldr  x4, [sp, #0xa0]
+
+    ; restore stack from GP + FPU
+    add  sp, sp, #0xb0
+
+    ret x4
diff --git a/lib/context_switcher/asm/fcontext/jump_arm_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_elf_gas.S
new file mode 100644
index 0000000..86efe9d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_elf_gas.S
@@ -0,0 +1,88 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  v7 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |  v8 |  lr |  pc | FCTX| DATA|                 |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "jump_arm_aapcs_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,%function
+.syntax unified
+jump_fcontext:
+    @ save LR as PC
+    push {lr}
+    @ save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    @ prepare stack for FPU
+    sub  sp, sp, #64
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ save S16-S31
+    vstmia sp, {d8-d15}
+#endif
+
+    @ store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    @ restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ restore S16-S31
+    vldmia  sp, {d8-d15}
+#endif
+    @ prepare stack for FPU
+    add  sp, sp, #64
+
+    @ restore hidden,V1-V8,LR
+    pop {a4,v1-v8,lr}
+
+    @ return transfer_t from jump
+    str  a1, [a4, #0]
+    str  a3, [a4, #4]
+    @ pass transfer_t as first arg in context function
+    @ A1 == FCTX, A2 == DATA
+    mov  a2, a3
+
+    @ restore PC
+    pop {pc}
+.size jump_fcontext,.-jump_fcontext
+
+@ Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_arm_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_macho_gas.S
new file mode 100644
index 0000000..8edd0d7
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_macho_gas.S
@@ -0,0 +1,95 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | sjlj|hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |  v7 |  v8 |  lr |  pc | FCTX| DATA|           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _jump_fcontext
+.align 2
+_jump_fcontext:
+    @ save LR as PC
+    push {lr}
+    @ save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    @ locate TLS to save/restore SjLj handler
+    mrc  p15, 0, v2, c13, c0, #3
+    bic  v2, v2, #3
+
+    @ load TLS[__PTK_LIBC_DYLD_Unwind_SjLj_Key]
+    ldr  v1, [v2, #8]
+    @ save SjLj handler
+    push  {v1}
+
+    @ prepare stack for FPU
+    sub  sp, sp, #64
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ save S16-S31
+    vstmia sp, {d8-d15}
+#endif
+
+    @ store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    @ restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ restore S16-S31
+    vldmia  sp, {d8-d15}
+#endif
+    @ prepare stack for FPU
+    add  sp, sp, #64
+
+    @ r#estore SjLj handler
+    pop  {v1}
+    @ store SjLj handler in TLS
+    str  v1, [v2, #8]
+
+    @ restore hidden,V1-V8,LR
+    pop {a4,v1-v8,lr}
+
+    @ return transfer_t from jump
+    str  a1, [a4, #0]
+    str  a3, [a4, #4]
+    @ pass transfer_t as first arg in context function
+    @ A1 == FCTX, A2 == DATA
+    mov  a2, a3
+
+    @ restore PC
+    pop {pc}
diff --git a/lib/context_switcher/asm/fcontext/jump_arm_aapcs_pe_armasm.asm b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_pe_armasm.asm
new file mode 100644
index 0000000..bca923c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_arm_aapcs_pe_armasm.asm
@@ -0,0 +1,81 @@
+;/*
+;            Copyright Oliver Kowalke 2009.
+;   Distributed under the Boost Software License, Version 1.0.
+;      (See accompanying file LICENSE_1_0.txt or copy at
+;          http://www.boost.org/LICENSE_1_0.txt)
+;*/
+
+; *******************************************************
+; *                                                     *
+; *  -------------------------------------------------  *
+; *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+; *  -------------------------------------------------  *
+; *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+; *  -------------------------------------------------  *
+; *  |deall|limit| base|hiddn|  v1 |  v2 |  v3 |  v4 |  *
+; *  -------------------------------------------------  *
+; *  -------------------------------------------------  *
+; *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+; *  -------------------------------------------------  *
+; *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+; *  -------------------------------------------------  *
+; *  |  v5 |  v6 |  v7 |  v8 |  lr |  pc | FCTX| DATA|  *
+; *  -------------------------------------------------  *
+; *                                                     *
+; *******************************************************
+
+    AREA |.text|, CODE
+    ALIGN 4
+    EXPORT jump_fcontext
+
+jump_fcontext PROC
+    ; save LR as PC
+    push {lr}
+    ; save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    ; load TIB to save/restore thread size and limit.
+    ; we do not need preserve CPU flag and can use it's arg register
+    mrc     p15, #0, v1, c13, c0, #2
+
+    ; save current stack base
+    ldr  a5, [v1, #0x04]
+    push {a5}
+    ; save current stack limit
+    ldr  a5, [v1, #0x08]
+    push {a5}
+    ; save current deallocation stack
+    ldr  a5, [v1, #0xe0c]
+    push {a5}
+
+    ; store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    ; restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+    ; restore deallocation stack
+    pop  {a5}
+    str  a5, [v1, #0xe0c]
+    ; restore stack limit
+    pop  {a5}
+    str  a5, [v1, #0x08]
+    ; restore stack base
+    pop  {a5}
+    str  a5, [v1, #0x04]
+
+    ; restore hidden,V1-V8,LR
+    pop {a4,v1-v8,lr}
+
+    ; return transfer_t from jump
+    str  a1, [a4, #0]
+    str  a3, [a4, #4]
+    ; pass transfer_t as first arg in context function
+    ; A1 == FCTX, A2 == DATA
+    mov  a2, a3
+
+    ; restore PC
+    pop {pc}
+
+    ENDP
+    END
diff --git a/lib/context_switcher/asm/fcontext/jump_combined_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_combined_sysv_macho_gas.S
new file mode 100644
index 0000000..1d27afa
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_combined_sysv_macho_gas.S
@@ -0,0 +1,20 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "jump_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "jump_x86_64_sysv_macho_gas.S"
+#elif defined(__ppc__)
+    #include "jump_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "jump_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_gas.asm
new file mode 100644
index 0000000..bf5c75a
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_gas.asm
@@ -0,0 +1,123 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+*  --------------------------------------------------------------------------------- *
+*  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    | *
+*  --------------------------------------------------------------------------------- *
+*  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  | *
+*  --------------------------------------------------------------------------------- *
+*  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   | *
+*  --------------------------------------------------------------------------------- *
+*  --------------------------------------------------------------------------------- *
+*  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   | *
+*  --------------------------------------------------------------------------------- *
+*  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  | *
+*  --------------------------------------------------------------------------------- *
+*  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR| *
+*  --------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"jump_i386_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+
+/* mark as using no unregistered SEH handlers */
+.globl	@feat.00
+.def	@feat.00;	.scl	3;	.type	0;	.endef
+.set    @feat.00,   1
+
+.globl	_jump_fcontext
+.def	_jump_fcontext;	.scl	2;	.type	32;	.endef
+_jump_fcontext:
+    /* prepare stack */
+    leal  -0x2c(%esp), %esp
+
+#if !defined(BOOST_USE_TSX)
+    /* save MMX control- and status-word */
+    stmxcsr  (%esp)
+    /* save x87 control-word */
+    fnstcw  0x4(%esp)
+#endif
+
+    /* load NT_TIB */
+    movl  %fs:(0x18), %edx
+    /* load fiber local storage */
+    movl  0x10(%edx), %eax
+    movl  %eax, 0x8(%esp)
+    /* load current dealloction stack */
+    movl  0xe0c(%edx), %eax
+    movl  %eax, 0xc(%esp)
+    /* load current stack limit */
+    movl  0x8(%edx), %eax
+    movl  %eax, 0x10(%esp)
+    /* load current stack base */
+    movl  0x4(%edx), %eax
+    movl  %eax, 0x14(%esp)
+    /* load current SEH exception list */
+    movl  (%edx), %eax
+    movl  %eax, 0x18(%esp)
+
+    movl  %edi, 0x1c(%esp)  /* save EDI */
+    movl  %esi, 0x20(%esp)  /* save ESI */
+    movl  %ebx, 0x24(%esp)  /* save EBX */
+    movl  %ebp, 0x28(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in EAX */
+    movl  %esp, %eax
+
+    /* firstarg of jump_fcontext() == fcontext to jump to */
+    movl  0x30(%esp), %ecx
+    
+    /* restore ESP (pointing to context-data) from ECX */
+    movl  %ecx, %esp
+
+#if !defined(BOOST_USE_TSX)
+    /* restore MMX control- and status-word */
+    ldmxcsr  (%esp)
+    /* restore x87 control-word */
+    fldcw  0x4(%esp)
+#endif
+
+    /* restore NT_TIB into EDX */
+    movl  %fs:(0x18), %edx
+    /* restore fiber local storage */
+    movl  0x8(%esp), %ecx
+    movl  %ecx, 0x10(%edx)
+    /* restore current deallocation stack */
+    movl  0xc(%esp), %ecx
+    movl  %ecx, 0xe0c(%edx)
+    /* restore current stack limit */
+    movl  0x10(%esp), %ecx
+    movl  %ecx, 0x8(%edx)
+    /* restore current stack base */
+    movl  0x14(%esp), %ecx
+    movl  %ecx, 0x4(%edx)
+    /* restore current SEH exception list */
+    movl  0x18(%esp), %ecx
+    movl  %ecx, (%edx)
+
+    movl  0x2c(%esp), %ecx  /* restore EIP */
+
+    movl  0x1c(%esp), %edi  /* restore EDI */
+    movl  0x20(%esp), %esi  /* restore ESI */
+    movl  0x24(%esp), %ebx  /* restore EBX */
+    movl  0x28(%esp), %ebp  /* restore EBP */
+
+    /* prepare stack */
+    leal  0x30(%esp), %esp
+
+    /* return transfer_t */
+    /* FCTX == EAX, DATA == EDX */
+    movl  0x34(%eax), %edx
+
+    /* jump to context */
+    jmp *%ecx
+
+.section .drectve
+.ascii " -export:\"_jump_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_masm.asm
new file mode 100644
index 0000000..7a9e848
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_i386_ms_pe_masm.asm
@@ -0,0 +1,116 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ---------------------------------------------------------------------------------
+;  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    |
+;  ---------------------------------------------------------------------------------
+;  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  |
+;  ---------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   |
+;  ---------------------------------------------------------------------------------
+;  ---------------------------------------------------------------------------------
+;  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   |
+;  ---------------------------------------------------------------------------------
+;  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  |
+;  ---------------------------------------------------------------------------------
+;  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR|
+;  ---------------------------------------------------------------------------------
+
+.386
+.XMM
+.model flat, c
+.code
+
+jump_fcontext PROC BOOST_CONTEXT_EXPORT
+    ; prepare stack
+    lea  esp, [esp-02ch]
+
+IFNDEF BOOST_USE_TSX
+    ; save MMX control- and status-word
+    stmxcsr  [esp]
+    ; save x87 control-word
+    fnstcw  [esp+04h]
+ENDIF
+
+    assume  fs:nothing
+    ; load NT_TIB into ECX
+    mov  edx, fs:[018h]
+    assume  fs:error
+    ; load fiber local storage
+    mov  eax, [edx+010h]
+    mov  [esp+08h], eax
+    ; load current deallocation stack
+    mov  eax, [edx+0e0ch]
+    mov  [esp+0ch], eax
+    ; load current stack limit
+    mov  eax, [edx+08h]
+    mov  [esp+010h], eax
+    ; load current stack base
+    mov  eax, [edx+04h]
+    mov  [esp+014h], eax
+    ; load current SEH exception list
+    mov  eax, [edx]
+    mov  [esp+018h], eax
+
+    mov  [esp+01ch], edi  ; save EDI 
+    mov  [esp+020h], esi  ; save ESI 
+    mov  [esp+024h], ebx  ; save EBX 
+    mov  [esp+028h], ebp  ; save EBP 
+
+    ; store ESP (pointing to context-data) in EAX
+    mov  eax, esp
+
+    ; firstarg of jump_fcontext() == fcontext to jump to
+    mov  ecx, [esp+030h]
+    
+    ; restore ESP (pointing to context-data) from ECX
+    mov  esp, ecx
+
+IFNDEF BOOST_USE_TSX
+    ; restore MMX control- and status-word
+    ldmxcsr  [esp]
+    ; restore x87 control-word
+    fldcw  [esp+04h]
+ENDIF
+
+    assume  fs:nothing
+    ; load NT_TIB into EDX
+    mov  edx, fs:[018h]
+    assume  fs:error
+    ; restore fiber local storage
+    mov  ecx, [esp+08h]
+    mov  [edx+010h], ecx
+    ; restore current deallocation stack
+    mov  ecx, [esp+0ch]
+    mov  [edx+0e0ch], ecx
+    ; restore current stack limit
+    mov  ecx, [esp+010h]
+    mov  [edx+08h], ecx
+    ; restore current stack base
+    mov  ecx, [esp+014h]
+    mov  [edx+04h], ecx
+    ; restore current SEH exception list
+    mov  ecx, [esp+018h]
+    mov  [edx], ecx
+
+    mov  ecx, [esp+02ch]  ; restore EIP
+
+    mov  edi, [esp+01ch]  ; restore EDI 
+    mov  esi, [esp+020h]  ; restore ESI 
+    mov  ebx, [esp+024h]  ; restore EBX 
+    mov  ebp, [esp+028h]  ; restore EBP 
+
+    ; prepare stack
+    lea  esp, [esp+030h]
+
+    ; return transfer_t
+    ; FCTX == EAX, DATA == EDX
+    mov  edx, [eax+034h]
+
+    ; jump to context
+    jmp ecx
+jump_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/jump_i386_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_i386_sysv_elf_gas.S
new file mode 100644
index 0000000..b96d4b5
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_i386_sysv_elf_gas.S
@@ -0,0 +1,83 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |  hidden |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    to   |   data  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "jump_i386_sysv_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,@function
+jump_fcontext:
+    leal  -0x18(%esp), %esp  /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%esp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%esp)  /* save x87 control-word */
+#endif
+
+    movl  %edi, 0x8(%esp)  /* save EDI */
+    movl  %esi, 0xc(%esp)  /* save ESI */
+    movl  %ebx, 0x10(%esp)  /* save EBX */
+    movl  %ebp, 0x14(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in ECX */
+    movl  %esp, %ecx
+
+    /* first arg of jump_fcontext() == fcontext to jump to */
+    movl  0x20(%esp), %eax
+
+    /* second arg of jump_fcontext() == data to be transferred */
+    movl  0x24(%esp), %edx
+
+    /* restore ESP (pointing to context-data) from EAX */
+    movl  %eax, %esp
+
+    /* address of returned transport_t */
+    movl 0x1c(%esp), %eax
+    /* return parent fcontext_t */
+    movl  %ecx, (%eax)
+    /* return data */
+    movl %edx, 0x4(%eax)
+
+    movl  0x18(%esp), %ecx  /* restore EIP */
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%esp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%esp)  /* restore x87 control-word */
+#endif
+
+    movl  0x8(%esp), %edi  /* restore EDI */
+    movl  0xc(%esp), %esi  /* restore ESI */
+    movl  0x10(%esp), %ebx  /* restore EBX */
+    movl  0x14(%esp), %ebp  /* restore EBP */
+
+    leal  0x20(%esp), %esp  /* prepare stack */
+
+    /* jump to context */
+    jmp *%ecx
+.size jump_fcontext,.-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_i386_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_i386_sysv_macho_gas.S
new file mode 100644
index 0000000..8ab7c6f
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_i386_sysv_macho_gas.S
@@ -0,0 +1,74 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |    to   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   data  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _jump_fcontext
+.align 2
+_jump_fcontext:
+    leal  -0x18(%esp), %esp  /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%esp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%esp)  /* save x87 control-word */
+#endif
+
+    movl  %edi, 0x8(%esp)  /* save EDI */
+    movl  %esi, 0xc(%esp)  /* save ESI */
+    movl  %ebx, 0x10(%esp)  /* save EBX */
+    movl  %ebp, 0x14(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in ECX */
+    movl  %esp, %ecx
+
+    /* first arg of jump_fcontext() == fcontext to jump to */
+    movl  0x1c(%esp), %eax
+
+    /* second arg of jump_fcontext() == data to be transferred */
+    movl  0x20(%esp), %edx
+
+    /* restore ESP (pointing to context-data) from EAX */
+    movl  %eax, %esp
+
+    /* return parent fcontext_t */
+    movl  %ecx, %eax
+    /* returned data is stored in EDX */ 
+ 
+    movl  0x18(%esp), %ecx  /* restore EIP */
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%esp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%esp)  /* restore x87 control-word */
+#endif
+
+    movl  0x8(%esp), %edi  /* restore EDI */
+    movl  0xc(%esp), %esi  /* restore ESI */
+    movl  0x10(%esp), %ebx  /* restore EBX */
+    movl  0x14(%esp), %ebp  /* restore EBP */
+
+    leal  0x1c(%esp), %esp  /* prepare stack */
+
+    /* jump to context */
+    jmp *%ecx
diff --git a/lib/context_switcher/asm/fcontext/jump_i386_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_i386_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..959ddac
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_i386_x86_64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "jump_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "jump_x86_64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/jump_mips32_o32_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_mips32_o32_elf_gas.S
new file mode 100644
index 0000000..f2b8034
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_mips32_o32_elf_gas.S
@@ -0,0 +1,119 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F20    |    F22    |    F24    |    F26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F30    |  S0 |  S1 |  S2 |  S3 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |  S4 |  S5 |  S6 |  S7 |  FP |hiddn|  RA |  PC |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |       ABI ARGS        |  GP | FCTX| DATA|     |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "jump_mips32_o32_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,@function
+.ent jump_fcontext
+jump_fcontext:
+    # reserve space on stack
+    addiu $sp, $sp, -96
+
+    sw  $s0, 48($sp)  # save S0
+    sw  $s1, 52($sp)  # save S1
+    sw  $s2, 56($sp)  # save S2
+    sw  $s3, 60($sp)  # save S3
+    sw  $s4, 64($sp)  # save S4
+    sw  $s5, 68($sp)  # save S5
+    sw  $s6, 72($sp)  # save S6
+    sw  $s7, 76($sp)  # save S7
+    sw  $fp, 80($sp)  # save FP
+    sw  $a0, 84($sp)  # save hidden, address of returned transfer_t
+    sw  $ra, 88($sp)  # save RA
+    sw  $ra, 92($sp)  # save RA as PC
+
+#if defined(__mips_hard_float)
+    s.d  $f20, ($sp)  # save F20
+    s.d  $f22, 8($sp)  # save F22
+    s.d  $f24, 16($sp)  # save F24
+    s.d  $f26, 24($sp)  # save F26
+    s.d  $f28, 32($sp)  # save F28
+    s.d  $f30, 40($sp)  # save F30
+#endif
+
+    # store SP (pointing to context-data) in A0
+    move  $a0, $sp
+
+    # restore SP (pointing to context-data) from A1
+    move  $sp, $a1
+
+#if defined(__mips_hard_float)
+    l.d  $f20, ($sp)  # restore F20
+    l.d  $f22, 8($sp)  # restore F22
+    l.d  $f24, 16($sp)  # restore F24
+    l.d  $f26, 24($sp)  # restore F26
+    l.d  $f28, 32($sp)  # restore F28
+    l.d  $f30, 40($sp)  # restore F30
+#endif
+
+    lw  $s0, 48($sp)  # restore S0
+    lw  $s1, 52($sp)  # restore S1
+    lw  $s2, 56($sp)  # restore S2
+    lw  $s3, 60($sp)  # restore S3
+    lw  $s4, 64($sp)  # restore S4
+    lw  $s5, 68($sp)  # restore S5
+    lw  $s6, 72($sp)  # restore S6
+    lw  $s7, 76($sp)  # restore S7
+    lw  $fp, 80($sp)  # restore FP
+    lw  $v0, 84($sp)  # restore hidden, address of returned transfer_t
+    lw  $ra, 88($sp)  # restore RA
+
+    # load PC
+    lw  $t9, 92($sp)
+
+    # adjust stack
+    addiu $sp, $sp, 96
+    
+    # return transfer_t from jump
+    sw  $a0, ($v0)  # fctx of transfer_t
+    sw  $a2, 4($v0) # data of transfer_t
+    # pass transfer_t as first arg in context function
+    # A0 == fctx, A1 == data
+    move  $a1, $a2 
+
+    # jump to context
+    jr  $t9
+.end jump_fcontext
+.size jump_fcontext, .-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_mips64_n64_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_mips64_n64_elf_gas.S
new file mode 100644
index 0000000..5423dd4
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_mips64_n64_elf_gas.S
@@ -0,0 +1,121 @@
+/*
+            Copyright Jiaxun Yang 2018.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    F24    |    F25    |    F26    |    F27    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F29    |    F30    |    F31    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    FP     |    GP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "jump_mips64_n64_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 3
+.type jump_fcontext,@function
+.ent jump_fcontext
+jump_fcontext:
+    # reserve space on stack
+    daddiu $sp, $sp, -160
+
+    sd  $s0, 64($sp)  # save S0
+    sd  $s1, 72($sp)  # save S1
+    sd  $s2, 80($sp)  # save S2
+    sd  $s3, 88($sp)  # save S3
+    sd  $s4, 96($sp)  # save S4
+    sd  $s5, 104($sp) # save S5
+    sd  $s6, 112($sp) # save S6
+    sd  $s7, 120($sp) # save S7
+    sd  $fp, 128($sp) # save FP
+    sd  $ra, 144($sp) # save RA
+    sd  $ra, 152($sp) # save RA as PC
+
+
+    s.d  $f24, 0($sp)   # save F24
+    s.d  $f25, 8($sp)   # save F25
+    s.d  $f26, 16($sp)  # save F26
+    s.d  $f27, 24($sp)  # save F27
+    s.d  $f28, 32($sp)  # save F28
+    s.d  $f29, 40($sp)  # save F29
+    s.d  $f30, 48($sp)  # save F30
+    s.d  $f31, 56($sp)  # save F31
+
+    # store SP (pointing to old context-data) in v0 as return
+    move  $v0, $sp
+
+    # get SP (pointing to new context-data) from a0 param
+    move  $sp, $a0
+
+    l.d  $f24, 0($sp)   # restore F24
+    l.d  $f25, 8($sp)   # restore F25
+    l.d  $f26, 16($sp)  # restore F26
+    l.d  $f27, 24($sp)  # restore F27
+    l.d  $f28, 32($sp)  # restore F28
+    l.d  $f29, 40($sp)  # restore F29
+    l.d  $f30, 48($sp)  # restore F30
+    l.d  $f31, 56($sp)  # restore F31
+
+    ld  $s0, 64($sp)  # restore S0
+    ld  $s1, 72($sp)  # restore S1
+    ld  $s2, 80($sp)  # restore S2
+    ld  $s3, 88($sp)  # restore S3
+    ld  $s4, 96($sp)  # restore S4
+    ld  $s5, 104($sp) # restore S5
+    ld  $s6, 112($sp) # restore S6
+    ld  $s7, 120($sp) # restore S7
+    ld  $fp, 128($sp) # restore FP
+    ld  $ra, 144($sp) # restore RAa
+
+    # load PC
+    ld  $t9, 152($sp)
+
+    # adjust stack
+    daddiu $sp, $sp, 160
+
+    move  $a0, $v0 # move old sp from v0 to a0 as param
+    move  $v1, $a1 # move *data from a1 to v1 as return
+
+    # jump to context
+    jr  $t9
+.end jump_fcontext
+.size jump_fcontext, .-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc32_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc32_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..f175e31
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc32_ppc64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__ppc__)
+    #include "jump_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "jump_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_elf_gas.S
new file mode 100644
index 0000000..48e09c9
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_elf_gas.S
@@ -0,0 +1,201 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |bchai|hiddn|   fpscr   |  PC |  CR | R14 | R15 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  | R16 | R17 | R18 | R19 | R20 | R21 | R22 | R23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  | R24 | R25 | R26 | R27 | R28 | R29 | R30 | R31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  ------------------------|------------              *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 |              *
+ *  ------------------------|------------              *
+ *  |    F30    |    F31    |bchai|  LR |              *
+ *  ------------------------|------------              *
+ *                                                     *
+ *******************************************************/
+
+.file "jump_ppc32_sysv_elf_gas.S"
+.text
+.globl jump_fcontext
+.align 2
+.type jump_fcontext,@function
+jump_fcontext:
+    # Linux: jump_fcontext( hidden transfer_t * R3, R4, R5)
+    # Other: transfer_t R3:R4 = jump_fcontext( R3, R4)
+
+    mflr  %r0  # return address from LR
+    mffs  %f0  # FPSCR
+    mfcr  %r8  # condition register
+
+    stwu  %r1, -240(%r1)  # allocate stack space, R1 % 16 == 0
+    stw   %r0, 244(%r1)   # save LR in caller's frame
+
+#ifdef __linux__
+    stw   %r3, 4(%r1)   # hidden pointer
+#endif
+
+    stfd  %f0, 8(%r1)   # FPSCR
+    stw   %r0, 16(%r1)  # LR as PC
+    stw   %r8, 20(%r1)  # CR
+
+    # Save registers R14 to R31.
+    # Don't change R2, the thread-local storage pointer.
+    # Don't change R13, the small data pointer.
+    stw   %r14, 24(%r1)
+    stw   %r15, 28(%r1)
+    stw   %r16, 32(%r1)
+    stw   %r17, 36(%r1)
+    stw   %r18, 40(%r1)
+    stw   %r19, 44(%r1)
+    stw   %r20, 48(%r1)
+    stw   %r21, 52(%r1)
+    stw   %r22, 56(%r1)
+    stw   %r23, 60(%r1)
+    stw   %r24, 64(%r1)
+    stw   %r25, 68(%r1)
+    stw   %r26, 72(%r1)
+    stw   %r27, 76(%r1)
+    stw   %r28, 80(%r1)
+    stw   %r29, 84(%r1)
+    stw   %r30, 88(%r1)
+    stw   %r31, 92(%r1)
+
+    # Save registers F14 to F31 in slots with 8-byte alignment.
+    # 4-byte alignment may stall the pipeline of some processors.
+    # Less than 4 may cause alignment traps.
+    stfd  %f14, 96(%r1)
+    stfd  %f15, 104(%r1)
+    stfd  %f16, 112(%r1)
+    stfd  %f17, 120(%r1)
+    stfd  %f18, 128(%r1)
+    stfd  %f19, 136(%r1)
+    stfd  %f20, 144(%r1)
+    stfd  %f21, 152(%r1)
+    stfd  %f22, 160(%r1)
+    stfd  %f23, 168(%r1)
+    stfd  %f24, 176(%r1)
+    stfd  %f25, 184(%r1)
+    stfd  %f26, 192(%r1)
+    stfd  %f27, 200(%r1)
+    stfd  %f28, 208(%r1)
+    stfd  %f29, 216(%r1)
+    stfd  %f30, 224(%r1)
+    stfd  %f31, 232(%r1)
+
+    # store RSP (pointing to context-data) in R7/R6
+    # restore RSP (pointing to context-data) from R4/R3
+#ifdef __linux__
+    mr   %r7, %r1
+    mr   %r1, %r4
+    lwz  %r3, 4(%r1)   # hidden pointer
+#else
+    mr   %r6, %r1
+    mr   %r1, %r3
+#endif
+
+    lfd  %f0, 8(%r1)   # FPSCR
+    lwz  %r0, 16(%r1)  # PC
+    lwz  %r8, 20(%r1)  # CR
+
+    mtfsf  0xff, %f0   # restore FPSCR
+    mtctr  %r0         # load CTR with PC
+    mtcr   %r8         # restore CR
+
+    # restore R14 to R31
+    lwz  %r14, 24(%r1)
+    lwz  %r15, 28(%r1)
+    lwz  %r16, 32(%r1)
+    lwz  %r17, 36(%r1)
+    lwz  %r18, 40(%r1)
+    lwz  %r19, 44(%r1)
+    lwz  %r20, 48(%r1)
+    lwz  %r21, 52(%r1)
+    lwz  %r22, 56(%r1)
+    lwz  %r23, 60(%r1)
+    lwz  %r24, 64(%r1)
+    lwz  %r25, 68(%r1)
+    lwz  %r26, 72(%r1)
+    lwz  %r27, 76(%r1)
+    lwz  %r28, 80(%r1)
+    lwz  %r29, 84(%r1)
+    lwz  %r30, 88(%r1)
+    lwz  %r31, 92(%r1)
+
+    # restore F14 to F31
+    lfd  %f14, 96(%r1)
+    lfd  %f15, 104(%r1)
+    lfd  %f16, 112(%r1)
+    lfd  %f17, 120(%r1)
+    lfd  %f18, 128(%r1)
+    lfd  %f19, 136(%r1)
+    lfd  %f20, 144(%r1)
+    lfd  %f21, 152(%r1)
+    lfd  %f22, 160(%r1)
+    lfd  %f23, 168(%r1)
+    lfd  %f24, 176(%r1)
+    lfd  %f25, 184(%r1)
+    lfd  %f26, 192(%r1)
+    lfd  %f27, 200(%r1)
+    lfd  %f28, 208(%r1)
+    lfd  %f29, 216(%r1)
+    lfd  %f30, 224(%r1)
+    lfd  %f31, 232(%r1)
+
+    # restore LR from caller's frame
+    lwz   %r0, 244(%r1)
+    mtlr  %r0
+
+    # adjust stack
+    addi  %r1, %r1, 240
+
+    # return transfer_t
+#ifdef __linux__
+    stw  %r7, 0(%r3)
+    stw  %r5, 4(%r3)
+#else
+    mr   %r3, %r6
+    #    %r4, %r4
+#endif
+
+    # jump to context
+    bctr
+.size jump_fcontext, .-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_macho_gas.S
new file mode 100644
index 0000000..c555237
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_macho_gas.S
@@ -0,0 +1,201 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _jump_fcontext
+.align 2
+_jump_fcontext:
+    ; reserve space on stack
+    subi  r1, r1, 244
+
+    stfd  f14, 0(r1)  # save F14
+    stfd  f15, 8(r1)  # save F15
+    stfd  f16, 16(r1)  # save F16
+    stfd  f17, 24(r1)  # save F17
+    stfd  f18, 32(r1)  # save F18
+    stfd  f19, 40(r1)  # save F19
+    stfd  f20, 48(r1)  # save F20
+    stfd  f21, 56(r1)  # save F21
+    stfd  f22, 64(r1)  # save F22
+    stfd  f23, 72(r1)  # save F23
+    stfd  f24, 80(r1)  # save F24
+    stfd  f25, 88(r1)  # save F25
+    stfd  f26, 96(r1)  # save F26
+    stfd  f27, 104(r1)  # save F27
+    stfd  f28, 112(r1)  # save F28
+    stfd  f29, 120(r1)  # save F29
+    stfd  f30, 128(r1)  # save F30
+    stfd  f31, 136(r1)  # save F31
+    mffs  f0  # load FPSCR
+    stfd  f0, 144(r1)  # save FPSCR
+
+    stw  r13, 152(r1)  # save R13
+    stw  r14, 156(r1)  # save R14
+    stw  r15, 160(r1)  # save R15
+    stw  r16, 164(r1)  # save R16
+    stw  r17, 168(r1)  # save R17
+    stw  r18, 172(r1)  # save R18
+    stw  r19, 176(r1)  # save R19
+    stw  r20, 180(r1)  # save R20
+    stw  r21, 184(r1)  # save R21
+    stw  r22, 188(r1)  # save R22
+    stw  r23, 192(r1)  # save R23
+    stw  r24, 196(r1)  # save R24
+    stw  r25, 200(r1)  # save R25
+    stw  r26, 204(r1)  # save R26
+    stw  r27, 208(r1)  # save R27
+    stw  r28, 212(r1)  # save R28
+    stw  r29, 216(r1)  # save R29
+    stw  r30, 220(r1)  # save R30
+    stw  r31, 224(r1)  # save R31
+    stw  r3,  228(r1)  # save hidden
+
+    # save CR
+    mfcr  r0
+    stw   r0, 232(r1)
+    # save LR
+    mflr  r0
+    stw   r0, 236(r1)
+    # save LR as PC
+    stw   r0, 240(r1)
+
+    # store RSP (pointing to context-data) in R6
+    mr  r6, r1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    lfd  f14, 0(r1)  # restore F14
+    lfd  f15, 8(r1)  # restore F15
+    lfd  f16, 16(r1)  # restore F16
+    lfd  f17, 24(r1)  # restore F17
+    lfd  f18, 32(r1)  # restore F18
+    lfd  f19, 40(r1)  # restore F19
+    lfd  f20, 48(r1)  # restore F20
+    lfd  f21, 56(r1)  # restore F21
+    lfd  f22, 64(r1)  # restore F22
+    lfd  f23, 72(r1)  # restore F23
+    lfd  f24, 80(r1)  # restore F24
+    lfd  f25, 88(r1)  # restore F25
+    lfd  f26, 96(r1)  # restore F26
+    lfd  f27, 104(r1)  # restore F27
+    lfd  f28, 112(r1)  # restore F28
+    lfd  f29, 120(r1)  # restore F29
+    lfd  f30, 128(r1)  # restore F30
+    lfd  f31, 136(r1)  # restore F31
+    lfd  f0,  144(r1)  # load FPSCR
+    mtfsf  0xff, f0  # restore FPSCR
+
+    lwz  r13, 152(r1)  # restore R13
+    lwz  r14, 156(r1)  # restore R14
+    lwz  r15, 160(r1)  # restore R15
+    lwz  r16, 164(r1)  # restore R16
+    lwz  r17, 168(r1)  # restore R17
+    lwz  r18, 172(r1)  # restore R18
+    lwz  r19, 176(r1)  # restore R19
+    lwz  r20, 180(r1)  # restore R20
+    lwz  r21, 184(r1)  # restore R21
+    lwz  r22, 188(r1)  # restore R22
+    lwz  r23, 192(r1)  # restore R23
+    lwz  r24, 196(r1)  # restore R24
+    lwz  r25, 200(r1)  # restore R25
+    lwz  r26, 204(r1)  # restore R26
+    lwz  r27, 208(r1)  # restore R27
+    lwz  r28, 212(r1)  # restore R28
+    lwz  r29, 216(r1)  # restore R29
+    lwz  r30, 220(r1)  # restore R30
+    lwz  r31, 224(r1)  # restore R31
+    lwz  r3,  228(r1)  # restore hidden
+
+    # restore CR
+    lwz   r0, 232(r1)
+    mtcr  r0
+    # restore LR
+    lwz   r0, 236(r1)
+    mtlr  r0
+    # load PC
+    lwz   r0, 240(r1)
+    # restore CTR
+    mtctr r0
+
+    # adjust stack
+    addi  r1, r1, 244
+
+    # return transfer_t 
+    stw  r6, 0(r3)
+    stw  r5, 4(r3)
+
+    # jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_xcoff_gas.S
new file mode 100644
index 0000000..5a96772
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc32_sysv_xcoff_gas.S
@@ -0,0 +1,203 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+.globl .jump_fcontext
+.globl  jump_fcontext[DS]
+.align 2 
+.csect	jump_fcontext[DS]
+jump_fcontext:
+  .long	.jump_fcontext
+.jump_fcontext:
+    # reserve space on stack
+    subi  r1, r1, 244
+
+    stfd  f14, 0(r1)  # save F14
+    stfd  f15, 8(r1)  # save F15
+    stfd  f16, 16(r1)  # save F16
+    stfd  f17, 24(r1)  # save F17
+    stfd  f18, 32(r1)  # save F18
+    stfd  f19, 40(r1)  # save F19
+    stfd  f20, 48(r1)  # save F20
+    stfd  f21, 56(r1)  # save F21
+    stfd  f22, 64(r1)  # save F22
+    stfd  f23, 72(r1)  # save F23
+    stfd  f24, 80(r1)  # save F24
+    stfd  f25, 88(r1)  # save F25
+    stfd  f26, 96(r1)  # save F26
+    stfd  f27, 104(r1)  # save F27
+    stfd  f28, 112(r1)  # save F28
+    stfd  f29, 120(r1)  # save F29
+    stfd  f30, 128(r1)  # save F30
+    stfd  f31, 136(r1)  # save F31
+    mffs  f0  # load FPSCR
+    stfd  f0, 144(r1)  # save FPSCR
+
+    stw  r13, 152(r1)  # save R13
+    stw  r14, 156(r1)  # save R14
+    stw  r15, 160(r1)  # save R15
+    stw  r16, 164(r1)  # save R16
+    stw  r17, 168(r1)  # save R17
+    stw  r18, 172(r1)  # save R18
+    stw  r19, 176(r1)  # save R19
+    stw  r20, 180(r1)  # save R20
+    stw  r21, 184(r1)  # save R21
+    stw  r22, 188(r1)  # save R22
+    stw  r23, 192(r1)  # save R23
+    stw  r24, 196(r1)  # save R24
+    stw  r25, 200(r1)  # save R25
+    stw  r26, 204(r1)  # save R26
+    stw  r27, 208(r1)  # save R27
+    stw  r28, 212(r1)  # save R28
+    stw  r29, 216(r1)  # save R29
+    stw  r30, 220(r1)  # save R30
+    stw  r31, 224(r1)  # save R31
+    stw  r3,  228(r1)  # save hidden
+
+    # save CR
+    mfcr  r0
+    stw   r0, 232(r1)
+    # save LR
+    mflr  r0
+    stw   r0, 236(r1)
+    # save LR as PC
+    stw   r0, 240(r1)
+
+    # store RSP (pointing to context-data) in R6
+    mr  r6, r1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    lfd  f14, 0(r1)  # restore F14
+    lfd  f15, 8(r1)  # restore F15
+    lfd  f16, 16(r1)  # restore F16
+    lfd  f17, 24(r1)  # restore F17
+    lfd  f18, 32(r1)  # restore F18
+    lfd  f19, 40(r1)  # restore F19
+    lfd  f20, 48(r1)  # restore F20
+    lfd  f21, 56(r1)  # restore F21
+    lfd  f22, 64(r1)  # restore F22
+    lfd  f23, 72(r1)  # restore F23
+    lfd  f24, 80(r1)  # restore F24
+    lfd  f25, 88(r1)  # restore F25
+    lfd  f26, 96(r1)  # restore F26
+    lfd  f27, 104(r1)  # restore F27
+    lfd  f28, 112(r1)  # restore F28
+    lfd  f29, 120(r1)  # restore F29
+    lfd  f30, 128(r1)  # restore F30
+    lfd  f31, 136(r1)  # restore F31
+    lfd  f0,  144(r1)  # load FPSCR
+    mtfsf  0xff, f0  # restore FPSCR
+
+    lwz  r13, 152(r1)  # restore R13
+    lwz  r14, 156(r1)  # restore R14
+    lwz  r15, 160(r1)  # restore R15
+    lwz  r16, 164(r1)  # restore R16
+    lwz  r17, 168(r1)  # restore R17
+    lwz  r18, 172(r1)  # restore R18
+    lwz  r19, 176(r1)  # restore R19
+    lwz  r20, 180(r1)  # restore R20
+    lwz  r21, 184(r1)  # restore R21
+    lwz  r22, 188(r1)  # restore R22
+    lwz  r23, 192(r1)  # restore R23
+    lwz  r24, 196(r1)  # restore R24
+    lwz  r25, 200(r1)  # restore R25
+    lwz  r26, 204(r1)  # restore R26
+    lwz  r27, 208(r1)  # restore R27
+    lwz  r28, 212(r1)  # restore R28
+    lwz  r29, 216(r1)  # restore R29
+    lwz  r30, 220(r1)  # restore R30
+    lwz  r31, 224(r1)  # restore R31
+    lwz  r3,  228(r1)  # restore hidden
+
+    # restore CR
+    lwz   r0, 232(r1)
+    mtcr  r0
+    # restore LR
+    lwz   r0, 236(r1)
+    mtlr  r0
+    # load PC
+    lwz   r0, 240(r1)
+    # restore CTR
+    mtctr r0
+
+    # adjust stack
+    addi  r1, r1, 244
+
+    # return transfer_t 
+    stw  r6, 0(r3)
+    stw  r5, 4(r3)
+
+    # jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_elf_gas.S
new file mode 100644
index 0000000..28907db
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_elf_gas.S
@@ -0,0 +1,221 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "jump_ppc64_sysv_elf_gas.S"
+.globl jump_fcontext
+#if _CALL_ELF == 2
+	.text
+	.align 2
+jump_fcontext:
+        addis   %r2, %r12, .TOC.-jump_fcontext@ha
+        addi    %r2, %r2, .TOC.-jump_fcontext@l
+        .localentry jump_fcontext, . - jump_fcontext
+#else
+	.section ".opd","aw"
+	.align 3
+jump_fcontext:
+# ifdef _CALL_LINUX
+        .quad   .L.jump_fcontext,.TOC.@tocbase,0
+        .type   jump_fcontext,@function
+        .text
+        .align 2
+.L.jump_fcontext:
+# else
+        .hidden .jump_fcontext
+        .globl  .jump_fcontext
+        .quad   .jump_fcontext,.TOC.@tocbase,0
+        .size   jump_fcontext,24
+        .type   .jump_fcontext,@function
+        .text
+        .align 2
+.jump_fcontext:
+# endif
+#endif
+    # reserve space on stack
+    subi  %r1, %r1, 184
+
+#if _CALL_ELF != 2
+    std  %r2,  0(%r1)  # save TOC
+#endif
+    std  %r14, 8(%r1)  # save R14
+    std  %r15, 16(%r1)  # save R15
+    std  %r16, 24(%r1)  # save R16
+    std  %r17, 32(%r1)  # save R17
+    std  %r18, 40(%r1)  # save R18
+    std  %r19, 48(%r1)  # save R19
+    std  %r20, 56(%r1)  # save R20
+    std  %r21, 64(%r1)  # save R21
+    std  %r22, 72(%r1)  # save R22
+    std  %r23, 80(%r1)  # save R23
+    std  %r24, 88(%r1)  # save R24
+    std  %r25, 96(%r1)  # save R25
+    std  %r26, 104(%r1)  # save R26
+    std  %r27, 112(%r1)  # save R27
+    std  %r28, 120(%r1)  # save R28
+    std  %r29, 128(%r1)  # save R29
+    std  %r30, 136(%r1)  # save R30
+    std  %r31, 144(%r1)  # save R31
+#if _CALL_ELF != 2
+    std  %r3,  152(%r1)  # save hidden
+#endif
+
+    # save CR
+    mfcr  %r0
+    std   %r0, 160(%r1)
+    # save LR
+    mflr  %r0
+    std   %r0, 168(%r1)
+    # save LR as PC
+    std   %r0, 176(%r1)
+
+    # store RSP (pointing to context-data) in R6
+    mr  %r6, %r1
+
+#if _CALL_ELF == 2
+    # restore RSP (pointing to context-data) from R3
+    mr  %r1, %r3
+#else
+    # restore RSP (pointing to context-data) from R4
+    mr  %r1, %r4
+
+    ld  %r2,  0(%r1)  # restore TOC
+#endif
+    ld  %r14, 8(%r1)  # restore R14
+    ld  %r15, 16(%r1)  # restore R15
+    ld  %r16, 24(%r1)  # restore R16
+    ld  %r17, 32(%r1)  # restore R17
+    ld  %r18, 40(%r1)  # restore R18
+    ld  %r19, 48(%r1)  # restore R19
+    ld  %r20, 56(%r1)  # restore R20
+    ld  %r21, 64(%r1)  # restore R21
+    ld  %r22, 72(%r1)  # restore R22
+    ld  %r23, 80(%r1)  # restore R23
+    ld  %r24, 88(%r1)  # restore R24
+    ld  %r25, 96(%r1)  # restore R25
+    ld  %r26, 104(%r1)  # restore R26
+    ld  %r27, 112(%r1)  # restore R27
+    ld  %r28, 120(%r1)  # restore R28
+    ld  %r29, 128(%r1)  # restore R29
+    ld  %r30, 136(%r1)  # restore R30
+    ld  %r31, 144(%r1)  # restore R31
+#if _CALL_ELF != 2
+    ld  %r3,  152(%r1)  # restore hidden
+#endif
+
+    # restore CR
+    ld  %r0, 160(%r1)
+    mtcr  %r0
+    # restore LR
+    ld  %r0, 168(%r1)
+    mtlr  %r0
+
+    # load PC
+    ld  %r12, 176(%r1)
+    # restore CTR
+    mtctr  %r12
+
+    # adjust stack
+    addi  %r1, %r1, 184
+
+#if _CALL_ELF == 2
+    # copy transfer_t into transfer_fn arg registers
+    mr  %r3, %r6
+    # arg pointer already in %r4
+
+    # jump to context
+    bctr
+	.size jump_fcontext, .-jump_fcontext
+#else
+    # zero in r3 indicates first jump to context-function
+    cmpdi %r3, 0
+    beq use_entry_arg
+
+    # return transfer_t
+    std  %r6, 0(%r3)
+    std  %r5, 8(%r3)
+
+    # jump to context
+    bctr
+
+use_entry_arg:
+    # copy transfer_t into transfer_fn arg registers
+    mr  %r3, %r6
+    mr  %r4, %r5
+
+    # jump to context
+    bctr
+# ifdef _CALL_LINUX
+	.size .jump_fcontext, .-.L.jump_fcontext
+# else
+	.size .jump_fcontext, .-.jump_fcontext
+# endif
+#endif
+
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..74fcb2a
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_macho_gas.S
@@ -0,0 +1,164 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.align 2
+.globl _jump_fcontext
+
+_jump_fcontext:
+    ; reserve space on stack
+    subi  r1, r1, 184
+
+    std  r14, 8(r1)  ; save R14
+    std  r15, 16(r1)  ; save R15
+    std  r16, 24(r1)  ; save R16
+    std  r17, 32(r1)  ; save R17
+    std  r18, 40(r1)  ; save R18
+    std  r19, 48(r1)  ; save R19
+    std  r20, 56(r1)  ; save R20
+    std  r21, 64(r1)  ; save R21
+    std  r22, 72(r1)  ; save R22
+    std  r23, 80(r1)  ; save R23
+    std  r24, 88(r1)  ; save R24
+    std  r25, 96(r1)  ; save R25
+    std  r26, 104(r1)  ; save R26
+    std  r27, 112(r1)  ; save R27
+    std  r28, 120(r1)  ; save R28
+    std  r29, 128(r1)  ; save R29
+    std  r30, 136(r1)  ; save R30
+    std  r31, 144(r1)  ; save R31
+    std  r3,  152(r1)  ; save hidden
+
+    ; save CR
+    mfcr  r0
+    std   r0, 160(r1)
+    ; save LR
+    mflr  r0
+    std   r0, 168(r1)
+    ; save LR as PC
+    std   r0, 176(r1)
+
+    ; store RSP (pointing to context-data) in R6
+    mr  r6, r1
+
+    ; restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    ld  r14, 8(r1)  ; restore R14
+    ld  r15, 16(r1)  ; restore R15
+    ld  r16, 24(r1)  ; restore R16
+    ld  r17, 32(r1)  ; restore R17
+    ld  r18, 40(r1)  ; restore R18
+    ld  r19, 48(r1)  ; restore R19
+    ld  r20, 56(r1)  ; restore R20
+    ld  r21, 64(r1)  ; restore R21
+    ld  r22, 72(r1)  ; restore R22
+    ld  r23, 80(r1)  ; restore R23
+    ld  r24, 88(r1)  ; restore R24
+    ld  r25, 96(r1)  ; restore R25
+    ld  r26, 104(r1)  ; restore R26
+    ld  r27, 112(r1)  ; restore R27
+    ld  r28, 120(r1)  ; restore R28
+    ld  r29, 128(r1)  ; restore R29
+    ld  r30, 136(r1)  ; restore R30
+    ld  r31, 144(r1)  ; restore R31
+    ld  r3,  152(r1)  ; restore hidden
+
+    ; restore CR
+    ld  r0, 160(r1)
+    mtcr  r0
+    ; restore LR
+    ld  r0, 168(r1)
+    mtlr  r0
+
+    ; load PC
+    ld  r12, 176(r1)
+    # restore CTR
+    mtctr  r12
+
+    # adjust stack
+    addi  r1, r1, 184
+
+    # zero in r3 indicates first jump to context-function
+    cmpdi r3, 0
+    beq use_entry_arg
+
+    # return transfer_t
+    std  r6, 0(r3)
+    std  r5, 8(r3)
+
+    # jump to context
+    bctr
+
+use_entry_arg:
+    # copy transfer_t into transfer_fn arg registers
+    mr  r3, r6
+    mr  r4, r5
+
+    # jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_xcoff_gas.S
new file mode 100644
index 0000000..ff0e6ea
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_ppc64_sysv_xcoff_gas.S
@@ -0,0 +1,92 @@
+
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+.align 2
+.globl .jump_fcontext
+.jump_fcontext:
+    # reserve space on stack
+    subi  1, 1, 184
+
+    std  13, 0(1)  # save R13
+    std  14, 8(1)  # save R14
+    std  15, 16(1)  # save R15
+    std  16, 24(1)  # save R16
+    std  17, 32(1)  # save R17
+    std  18, 40(1)  # save R18
+    std  19, 48(1)  # save R19
+    std  20, 56(1)  # save R20
+    std  21, 64(1)  # save R21
+    std  22, 72(1)  # save R22
+    std  23, 80(1)  # save R23
+    std  24, 88(1)  # save R24
+    std  25, 96(1)  # save R25
+    std  26, 104(1)  # save R26
+    std  27, 112(1)  # save R27
+    std  29, 120(1)  # save R28
+    std  29, 128(1)  # save R29
+    std  30, 136(1)  # save R30
+    std  31, 144(1)  # save R31
+    std  3,  152(1)  # save hidden
+
+    # save CR
+    mfcr  0
+    std  0, 160(1)
+    # save LR
+    mflr  0
+    std  0, 168(1)
+    # save LR as PC
+    std  0, 176(1)
+
+    # store RSP (pointing to context-data) in R6
+    mr  6, 1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  1, 4
+
+    ld  13, 0(1)  # restore R13
+    ld  14, 8(1)  # restore R14
+    ld  15, 16(1)  # restore R15
+    ld  16, 24(1)  # restore R16
+    ld  17, 32(1)  # restore R17
+    ld  18, 40(1)  # restore R18
+    ld  19, 48(1)  # restore R19
+    ld  20, 56(1)  # restore R20
+    ld  21, 64(1)  # restore R21
+    ld  22, 72(1)  # restore R22
+    ld  23, 80(1)  # restore R23
+    ld  24, 88(1)  # restore R24
+    ld  25, 96(1)  # restore R25
+    ld  26, 104(1)  # restore R26
+    ld  27, 112(1)  # restore R27
+    ld  28, 120(1)  # restore R28
+    ld  29, 128(1)  # restore R29
+    ld  30, 136(1)  # restore R30
+    ld  31, 144(1)  # restore R31
+    ld  3,  152(1)  # restore hidden
+
+    # restore CR
+    ld  0, 160(1)
+    mtcr  0
+    # restore LR
+    ld  0, 168(1)
+    mtlr  0
+
+    # load PC
+    ld  0, 176(1)
+    # restore CTR
+    mtctr  0
+
+    # adjust stack
+    addi  1, 1, 184
+
+    # return transfer_t
+    std  6, 0(3)
+    std  5, 8(3)
+
+    # jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/jump_riscv64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_riscv64_sysv_elf_gas.S
new file mode 100644
index 0000000..5417e5d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_riscv64_sysv_elf_gas.S
@@ -0,0 +1,150 @@
+/*
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    fs0    |    fs1    |    fs2    |    fs3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    fs4    |    fs5    |    fs6    |    fs7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    fs8    |    fs9    |    fs10   |    fs11   |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    s0     |    s1     |    s2     |    s3     |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    s4     |    s5     |    s6     |     s7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |  44 | 45  |  46 | 47  |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac| 0xb0| 0xb4| 0xb8| 0xbc|  *
+ *  -------------------------------------------------  *
+ *  |     s8    |     s9    |    s10    |    s11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 | 51  |     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  | 0xc0| 0xc4| 0xc8| 0xcc|     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  |     ra    |     pc    |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "jump_riscv64_sysv_elf_gas.S"
+.text
+.align  1
+.global jump_fcontext
+.type   jump_fcontext, %function
+jump_fcontext:
+    # prepare stack for GP + FPU
+    addi  sp, sp, -0xd0
+
+    # save fs0 - fs11
+    fsd  fs0, 0x00(sp)
+    fsd  fs1, 0x08(sp)
+    fsd  fs2, 0x10(sp)
+    fsd  fs3, 0x18(sp)
+    fsd  fs4, 0x20(sp)
+    fsd  fs5, 0x28(sp)
+    fsd  fs6, 0x30(sp)
+    fsd  fs7, 0x38(sp)
+    fsd  fs8, 0x40(sp)
+    fsd  fs9, 0x48(sp)
+    fsd  fs10, 0x50(sp)
+    fsd  fs11, 0x58(sp)
+
+    # save s0-s11, ra
+    sd  s0, 0x60(sp)
+    sd  s1, 0x68(sp)
+    sd  s2, 0x70(sp)
+    sd  s3, 0x78(sp)
+    sd  s4, 0x80(sp)
+    sd  s5, 0x88(sp)
+    sd  s6, 0x90(sp)
+    sd  s7, 0x98(sp)
+    sd  s8, 0xa0(sp)
+    sd  s9, 0xa8(sp)
+    sd  s10, 0xb0(sp)
+    sd  s11, 0xb8(sp)
+    sd  ra, 0xc0(sp)
+
+    # save RA as PC
+    sd  ra, 0xc8(sp)
+
+    # store SP (pointing to context-data) in A2
+    mv  a2, sp
+
+    # restore SP (pointing to context-data) from A0
+    mv  sp, a0
+
+    # load fs0 - fs11
+    fld  fs0, 0x00(sp)
+    fld  fs1, 0x08(sp)
+    fld  fs2, 0x10(sp)
+    fld  fs3, 0x18(sp)
+    fld  fs4, 0x20(sp)
+    fld  fs5, 0x28(sp)
+    fld  fs6, 0x30(sp)
+    fld  fs7, 0x38(sp)
+    fld  fs8, 0x40(sp)
+    fld  fs9, 0x48(sp)
+    fld  fs10, 0x50(sp)
+    fld  fs11, 0x58(sp)
+
+    # load s0-s11,ra
+    ld  s0, 0x60(sp)
+    ld  s1, 0x68(sp)
+    ld  s2, 0x70(sp)
+    ld  s3, 0x78(sp)
+    ld  s4, 0x80(sp)
+    ld  s5, 0x88(sp)
+    ld  s6, 0x90(sp)
+    ld  s7, 0x98(sp)
+    ld  s8, 0xa0(sp)
+    ld  s9, 0xa8(sp)
+    ld  s10, 0xb0(sp)
+    ld  s11, 0xb8(sp)
+    ld  ra, 0xc0(sp)
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # a0 == FCTX, a1 == DATA
+    mv a0, a2
+
+    # load pc
+    ld  a2, 0xc8(sp)
+
+    # restore stack from GP + FPU
+    addi  sp, sp, 0xd0
+
+    jr a2
+.size   jump_fcontext,.-jump_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_s390x_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_s390x_sysv_elf_gas.S
new file mode 100644
index 0000000..b2163cc
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_s390x_sysv_elf_gas.S
@@ -0,0 +1,117 @@
+/*******************************************************
+*                                                     *
+*  -------------------------------------------------  *
+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+*  -------------------------------------------------  *
+*  |     0     |     8     |    16     |     24    |  *
+*  -------------------------------------------------  *
+*  |    R6     |    R7     |    R8     |    R9     |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+*  -------------------------------------------------  *
+*  |     32    |    40     |     48    |     56    |  *
+*  -------------------------------------------------  *
+*  |    R10    |    R11    |     R12   |     R13   |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+*  -------------------------------------------------  *
+*  |     64    |    72     |     80    |     88    |  *
+*  -------------------------------------------------  *
+*  |   R14/LR  |    R15    |     F1    |     F3    |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *
+*  -------------------------------------------------  *
+*  |     96    |    104    |    112    |    120    |  *
+*  -------------------------------------------------  *
+*  |    F5     |    F7     |     PC    |           |  *
+*  -------------------------------------------------  *
+* *****************************************************/
+
+.file  "jump_s390x_sysv_elf_gas.S"
+.text
+.align  4 # According to the sample code in the ELF ABI docs
+.global jump_fcontext
+.type   jump_fcontext, @function
+
+#define GR_OFFSET	0
+#define LR_OFFSET	64
+#define SP_OFFSET	72
+#define FP_OFFSET	80
+#define PC_OFFSET	112
+#define L_CTX		120
+#define L_STACKFRAME	120
+
+jump_fcontext:
+    
+    # Reserved the space for stack to store the data of current context
+    # before we jump to the new context.
+    aghi %r15,-L_STACKFRAME
+
+    # save the registers to the stack
+    stmg %r6, %r15, GR_OFFSET(%r15)
+
+    # save the floating point registers
+    std  %f0,FP_OFFSET(%r15)
+    std  %f3,FP_OFFSET+8(%r15)
+    std  %f5,FP_OFFSET+16(%r15)
+    std  %f7,FP_OFFSET+24(%r15)
+
+    # Save LR as PC
+    stg  %r14,PC_OFFSET(%r15)
+
+    # Store the SP pointing to the old context-data into R0
+    lgr	 %r0,%r15
+
+    # Get the SP pointing to the new context-data
+    # Note: Since the return type of the jump_fcontext is struct whose
+    # size is more than 8. The compiler automatically passes the 
+    # address of the transfer_t where the data needs to store into R2.
+
+    # Hence the first param passed to the jump_fcontext which represent
+    # the fctx we want to switch to is present in R3
+    # R2 --> Address of the return transfer_t struct
+    # R3 --> Context we want to switch to
+    # R4 --> Data
+    lgr	%r15,%r3
+
+    # Load the registers with the data present in context-data of the
+    # context we are going to switch to
+    lmg	%r6, %r14, GR_OFFSET(%r15)
+
+    # Restore Floating point registers
+    ld	 %f1,FP_OFFSET(%r15)
+    ld	 %f3,FP_OFFSET+8(%r15)
+    ld	 %f5,FP_OFFSET+16(%r15)
+    ld	 %f7,FP_OFFSET+24(%r15)
+
+    # Load PC
+    lg   %r1,PC_OFFSET(%r15)
+
+    # Adjust the stack 
+    aghi %r15,120
+
+    # R2 --> Address where the return transfer_t is stored
+    # R0 --> FCTX
+    # R4 --> DATA
+
+    # Store the elements to return transfer_t
+    stg %r15, 0(%r2)
+    stg %r4, 8(%r2)
+
+    # Note: The address in R2 points to the place where the return
+    # transfer_t is stored. Since context_function take transfer_t
+    # as first parameter. And R2 is the register which holds the
+    # first parameter value.
+
+    #jump to context
+    br  %r1
+
+.size   jump_fcontext,.-jump_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
+
+
+
diff --git a/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_gas.asm
new file mode 100644
index 0000000..ec4ecfe
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_gas.asm
@@ -0,0 +1,209 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+* ---------------------------------------------------------------------------------- *
+* |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   | *
+* ---------------------------------------------------------------------------------- *
+* |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  | *
+* ---------------------------------------------------------------------------------- *
+* | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  | *
+* ---------------------------------------------------------------------------------- *
+* |        limit      |         base       |         R12       |         R13       | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  | *
+* ---------------------------------------------------------------------------------- *
+* |        R14        |         R15        |         RDI       |        RSI        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  | *
+* ---------------------------------------------------------------------------------- *
+* |        RBX        |         RBP        |       hidden      |        RIP        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  | *
+* ---------------------------------------------------------------------------------- *
+* |                                   parameter area                               | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  | *
+* ---------------------------------------------------------------------------------- *
+* |       FCTX        |        DATA        |                                       | *
+* ---------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"jump_x86_64_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+.globl	jump_fcontext
+.def	jump_fcontext;	.scl	2;	.type	32;	.endef
+.seh_proc	jump_fcontext
+jump_fcontext:
+.seh_endprologue
+
+    leaq  -0x118(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    /* save XMM storage */
+    movaps  %xmm6, 0x0(%rsp)
+    movaps  %xmm7, 0x10(%rsp)
+    movaps  %xmm8, 0x20(%rsp)
+    movaps  %xmm9, 0x30(%rsp)
+    movaps  %xmm10, 0x40(%rsp)
+    movaps  %xmm11, 0x50(%rsp)
+    movaps  %xmm12, 0x60(%rsp)
+    movaps  %xmm13, 0x70(%rsp)
+    movaps  %xmm14, 0x80(%rsp)
+    movaps  %xmm15, 0x90(%rsp)
+    stmxcsr  0xa0(%rsp)  /* save MMX control- and status-word */
+    fnstcw   0xa4(%rsp)  /* save x87 control-word */
+#endif
+
+    /* load NT_TIB */
+    movq  %gs:(0x30), %r10
+    /* save fiber local storage */
+    movq  0x20(%r10), %rax
+    movq  %rax, 0xb0(%rsp)
+    /* save current deallocation stack */
+    movq  0x1478(%r10), %rax
+    movq  %rax, 0xb8(%rsp)
+    /* save current stack limit */
+    movq  0x10(%r10), %rax
+    movq  %rax, 0xc0(%rsp)
+    /* save current stack base */
+    movq  0x08(%r10), %rax
+    movq  %rax, 0xc8(%rsp)
+
+    movq  %r12, 0xd0(%rsp)  /* save R12 */
+    movq  %r13, 0xd8(%rsp)  /* save R13 */
+    movq  %r14, 0xe0(%rsp)  /* save R14 */
+    movq  %r15, 0xe8(%rsp)  /* save R15 */
+    movq  %rdi, 0xf0(%rsp)  /* save RDI */
+    movq  %rsi, 0xf8(%rsp)  /* save RSI */
+    movq  %rbx, 0x100(%rsp)  /* save RBX */
+    movq  %rbp, 0x108(%rsp)  /* save RBP */
+
+    movq  %rcx, 0x110(%rsp)  /* save hidden address of transport_t */
+
+    /* preserve RSP (pointing to context-data) in R9 */
+    movq  %rsp, %r9
+
+    /* restore RSP (pointing to context-data) from RDX */
+    movq  %rdx, %rsp
+
+#if !defined(BOOST_USE_TSX)
+    /* restore XMM storage */
+    movaps  0x0(%rsp), %xmm6
+    movaps  0x10(%rsp), %xmm7
+    movaps  0x20(%rsp), %xmm8
+    movaps  0x30(%rsp), %xmm9
+    movaps  0x40(%rsp), %xmm10
+    movaps  0x50(%rsp), %xmm11
+    movaps  0x60(%rsp), %xmm12
+    movaps  0x70(%rsp), %xmm13
+    movaps  0x80(%rsp), %xmm14
+    movaps  0x90(%rsp), %xmm15
+ 	ldmxcsr 0xa0(%rsp) /* restore MMX control- and status-word */
+ 	fldcw   0xa4(%rsp) /* restore x87 control-word */
+#endif
+
+    /* load NT_TIB */
+    movq  %gs:(0x30), %r10
+    /* restore fiber local storage */
+    movq  0xb0(%rsp), %rax
+    movq  %rax, 0x20(%r10)
+    /* restore current deallocation stack */
+    movq  0xb8(%rsp), %rax
+    movq  %rax, 0x1478(%r10)
+    /* restore current stack limit */
+    movq  0xc0(%rsp), %rax
+    movq  %rax, 0x10(%r10)
+    /* restore current stack base */
+    movq  0xc8(%rsp), %rax
+    movq  %rax, 0x08(%r10)
+
+    movq  0xd0(%rsp),  %r12  /* restore R12 */
+    movq  0xd8(%rsp),  %r13  /* restore R13 */
+    movq  0xe0(%rsp),  %r14  /* restore R14 */
+    movq  0xe8(%rsp),  %r15  /* restore R15 */
+    movq  0xf0(%rsp),  %rdi  /* restore RDI */
+    movq  0xf8(%rsp),  %rsi  /* restore RSI */
+    movq  0x100(%rsp), %rbx  /* restore RBX */
+    movq  0x108(%rsp), %rbp  /* restore RBP */
+
+    movq  0x110(%rsp), %rax  /* restore hidden address of transport_t */
+
+    leaq  0x118(%rsp), %rsp /* prepare stack */
+
+    /* restore return-address */
+    popq  %r10
+
+    /* transport_t returned in RAX */
+    /* return parent fcontext_t */
+    movq  %r9, 0x0(%rax)
+    /* return data */
+    movq  %r8, 0x8(%rax)
+
+    /* transport_t as 1.arg of context-function */
+    movq  %rax, %rcx
+
+    /* indirect jump to context */
+    jmp  *%r10
+.seh_endproc
+
+.section .drectve
+.ascii " -export:\"jump_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_masm.asm
new file mode 100644
index 0000000..c8a28a5
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_x86_64_ms_pe_masm.asm
@@ -0,0 +1,205 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ----------------------------------------------------------------------------------
+;  |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   |
+;  ----------------------------------------------------------------------------------
+;  |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   |
+;  ----------------------------------------------------------------------------------
+;  |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   |
+;  ----------------------------------------------------------------------------------
+;  |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   |
+;  ----------------------------------------------------------------------------------
+;  |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   |
+;  ----------------------------------------------------------------------------------
+;  |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  |
+;  ----------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   |
+;  ----------------------------------------------------------------------------------
+;  |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  |
+;  ----------------------------------------------------------------------------------
+;  |        limit      |         base       |         R12       |         R13       |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  |
+;  ----------------------------------------------------------------------------------
+;  |        R14        |         R15        |         RDI       |        RSI        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   |
+;  ----------------------------------------------------------------------------------
+;  |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  |
+;  ----------------------------------------------------------------------------------
+;  |        RBX        |         RBP        |       hidden      |        RIP        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   |
+;  ----------------------------------------------------------------------------------
+;  |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  |
+;  ----------------------------------------------------------------------------------
+;  |                                   parameter area                               |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   |
+;  ----------------------------------------------------------------------------------
+;  |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  |
+;  ----------------------------------------------------------------------------------
+;  |       FCTX        |        DATA        |                                       |
+;  ----------------------------------------------------------------------------------
+
+.code
+
+jump_fcontext PROC BOOST_CONTEXT_EXPORT FRAME
+    .endprolog
+
+    ; prepare stack
+    lea rsp, [rsp-0118h]
+
+IFNDEF BOOST_USE_TSX
+    ; save XMM storage
+    movaps  [rsp], xmm6
+    movaps  [rsp+010h], xmm7
+    movaps  [rsp+020h], xmm8
+    movaps  [rsp+030h], xmm9
+    movaps  [rsp+040h], xmm10
+    movaps  [rsp+050h], xmm11
+    movaps  [rsp+060h], xmm12
+    movaps  [rsp+070h], xmm13
+    movaps  [rsp+080h], xmm14
+    movaps  [rsp+090h], xmm15
+    ; save MMX control- and status-word
+    stmxcsr  [rsp+0a0h]
+    ; save x87 control-word
+    fnstcw  [rsp+0a4h]
+ENDIF
+
+    ; load NT_TIB
+    mov  r10,  gs:[030h]
+    ; save fiber local storage
+    mov  rax, [r10+020h]
+    mov  [rsp+0b0h], rax
+    ; save current deallocation stack
+    mov  rax, [r10+01478h]
+    mov  [rsp+0b8h], rax
+    ; save current stack limit
+    mov  rax, [r10+010h]
+    mov  [rsp+0c0h], rax
+    ; save current stack base
+    mov  rax,  [r10+08h]
+    mov  [rsp+0c8h], rax
+
+    mov [rsp+0d0h], r12  ; save R12
+    mov [rsp+0d8h], r13  ; save R13
+    mov [rsp+0e0h], r14  ; save R14
+    mov [rsp+0e8h], r15  ; save R15
+    mov [rsp+0f0h], rdi  ; save RDI
+    mov [rsp+0f8h], rsi  ; save RSI
+    mov [rsp+0100h], rbx  ; save RBX
+    mov [rsp+0108h], rbp  ; save RBP
+
+    mov [rsp+0110h], rcx  ; save hidden address of transport_t
+
+    ; preserve RSP (pointing to context-data) in R9
+    mov  r9, rsp
+
+    ; restore RSP (pointing to context-data) from RDX
+    mov  rsp, rdx
+
+IFNDEF BOOST_USE_TSX
+    ; restore XMM storage
+    movaps  xmm6, [rsp]
+    movaps  xmm7, [rsp+010h]
+    movaps  xmm8, [rsp+020h]
+    movaps  xmm9, [rsp+030h]
+    movaps  xmm10, [rsp+040h]
+    movaps  xmm11, [rsp+050h]
+    movaps  xmm12, [rsp+060h]
+    movaps  xmm13, [rsp+070h]
+    movaps  xmm14, [rsp+080h]
+    movaps  xmm15, [rsp+090h]
+    ; restore MMX control- and status-word
+    ldmxcsr  [rsp+0a0h]
+    ; save x87 control-word
+    fldcw   [rsp+0a4h]
+ENDIF
+
+    ; load NT_TIB
+    mov  r10,  gs:[030h]
+    ; restore fiber local storage
+    mov  rax, [rsp+0b0h]
+    mov  [r10+020h], rax
+    ; restore current deallocation stack
+    mov  rax, [rsp+0b8h]
+    mov  [r10+01478h], rax
+    ; restore current stack limit
+    mov  rax, [rsp+0c0h]
+    mov  [r10+010h], rax
+    ; restore current stack base
+    mov  rax, [rsp+0c8h]
+    mov  [r10+08h], rax
+
+    mov r12, [rsp+0d0h]  ; restore R12
+    mov r13, [rsp+0d8h]  ; restore R13
+    mov r14, [rsp+0e0h]  ; restore R14
+    mov r15, [rsp+0e8h]  ; restore R15
+    mov rdi, [rsp+0f0h]  ; restore RDI
+    mov rsi, [rsp+0f8h]  ; restore RSI
+    mov rbx, [rsp+0100h]  ; restore RBX
+    mov rbp, [rsp+0108h]  ; restore RBP
+
+    mov rax, [rsp+0110h] ; restore hidden address of transport_t
+
+    ; prepare stack
+    lea rsp, [rsp+0118h]
+
+    ; load return-address
+    pop  r10
+
+    ; transport_t returned in RAX
+    ; return parent fcontext_t
+    mov  [rax], r9
+    ; return data
+    mov  [rax+08h], r8
+
+    ; transport_t as 1.arg of context-function
+    mov  rcx,  rax
+
+    ; indirect jump to context
+    jmp  r10
+jump_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_elf_gas.S
new file mode 100644
index 0000000..d0defc4
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_elf_gas.S
@@ -0,0 +1,81 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "jump_x86_64_sysv_elf_gas.S"
+.text
+.globl jump_fcontext
+.type jump_fcontext,@function
+.align 16
+jump_fcontext:
+    leaq  -0x38(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%rsp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%rsp)  /* save x87 control-word */
+#endif
+
+    movq  %r12, 0x8(%rsp)  /* save R12 */
+    movq  %r13, 0x10(%rsp)  /* save R13 */
+    movq  %r14, 0x18(%rsp)  /* save R14 */
+    movq  %r15, 0x20(%rsp)  /* save R15 */
+    movq  %rbx, 0x28(%rsp)  /* save RBX */
+    movq  %rbp, 0x30(%rsp)  /* save RBP */
+
+    /* store RSP (pointing to context-data) in RAX */
+    movq  %rsp, %rax
+
+    /* restore RSP (pointing to context-data) from RDI */
+    movq  %rdi, %rsp
+
+    movq  0x38(%rsp), %r8  /* restore return-address */
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%rsp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%rsp)  /* restore x87 control-word */
+#endif
+
+    movq  0x8(%rsp), %r12  /* restore R12 */
+    movq  0x10(%rsp), %r13  /* restore R13 */
+    movq  0x18(%rsp), %r14  /* restore R14 */
+    movq  0x20(%rsp), %r15  /* restore R15 */
+    movq  0x28(%rsp), %rbx  /* restore RBX */
+    movq  0x30(%rsp), %rbp  /* restore RBP */
+
+    leaq  0x40(%rsp), %rsp /* prepare stack */
+
+    /* return transfer_t from jump */
+    /* RAX == fctx, RDX == data */
+    movq  %rsi, %rdx
+    /* pass transfer_t as first arg in context function */
+    /* RDI == fctx, RSI == data */
+    movq  %rax, %rdi
+
+    /* indirect jump to context */
+    jmp  *%r8
+.size jump_fcontext,.-jump_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..afc3e5c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/jump_x86_64_sysv_macho_gas.S
@@ -0,0 +1,75 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _jump_fcontext
+.align 8
+_jump_fcontext:
+    leaq  -0x38(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%rsp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%rsp)  /* save x87 control-word */
+#endif
+
+    movq  %r12, 0x8(%rsp)  /* save R12 */
+    movq  %r13, 0x10(%rsp)  /* save R13 */
+    movq  %r14, 0x18(%rsp)  /* save R14 */
+    movq  %r15, 0x20(%rsp)  /* save R15 */
+    movq  %rbx, 0x28(%rsp)  /* save RBX */
+    movq  %rbp, 0x30(%rsp)  /* save RBP */
+
+    /* store RSP (pointing to context-data) in RAX */
+    movq  %rsp, %rax
+
+    /* restore RSP (pointing to context-data) from RDI */
+    movq  %rdi, %rsp
+
+    movq  0x38(%rsp), %r8  /* restore return-address */
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%rsp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%rsp)  /* restore x87 control-word */
+#endif
+
+    movq  0x8(%rsp), %r12  /* restore R12 */
+    movq  0x10(%rsp), %r13  /* restore R13 */
+    movq  0x18(%rsp), %r14  /* restore R14 */
+    movq  0x20(%rsp), %r15  /* restore R15 */
+    movq  0x28(%rsp), %rbx  /* restore RBX */
+    movq  0x30(%rsp), %rbp  /* restore RBP */
+
+    leaq  0x40(%rsp), %rsp /* prepare stack */
+
+    /* return transfer_t from jump */
+    /* RAX == fctx, RDX == data */
+    movq  %rsi, %rdx
+    /* pass transfer_t as first arg in context function */
+    /* RDI == fctx, RSI == data */
+    movq  %rax, %rdi
+
+    /* indirect jump to context */
+    jmp  *%r8
diff --git a/lib/context_switcher/asm/fcontext/make_arm64_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/make_arm64_aapcs_elf_gas.S
new file mode 100644
index 0000000..66cfb2d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_arm64_aapcs_elf_gas.S
@@ -0,0 +1,85 @@
+/*
+            Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "make_arm64_aapcs_elf_gas.S"
+.text
+.align  2
+.global make_fcontext
+.type   make_fcontext, %function
+make_fcontext:
+    # shift address in x0 (allocated stack) to lower 16 byte boundary
+    and x0, x0, ~0xF
+
+    # reserve space for context-data on context-stack
+    sub  x0, x0, #0xb0
+
+    # third arg of make_fcontext() == address of context-function
+    # store address as a PC to jump in
+    str  x2, [x0, #0xa0]
+
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns (LR register)
+    adr  x1, finish
+    str  x1, [x0, #0x98]
+
+    ret  x30 // return pointer to context-data (x0)
+
+finish:
+    # exit code is zero
+    mov  x0, #0
+    # exit application
+    bl  _exit
+
+.size   make_fcontext,.-make_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_arm64_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/make_arm64_aapcs_macho_gas.S
new file mode 100644
index 0000000..a3716ff
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_arm64_aapcs_macho_gas.S
@@ -0,0 +1,88 @@
+/*
+            Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _make_fcontext
+.balign 16
+
+_make_fcontext:
+    ; shift address in x0 (allocated stack) to lower 16 byte boundary
+    and x0, x0, ~0xF
+
+    ; reserve space for context-data on context-stack
+    sub  x0, x0, #0xb0
+
+    ; third arg of make_fcontext() == address of context-function
+    ; store address as a PC to jump in
+    str  x2, [x0, #0xa0]
+
+    ; compute abs address of label finish
+    ; 0x0c = 3 instructions * size (4) before label 'finish'
+
+    ; TODO: Numeric offset since llvm still does not support labels in ADR. Fix:
+    ;       http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140407/212336.html
+    adr  x1, 0x0c
+
+    ; save address of finish as return-address for context-function
+    ; will be entered after context-function returns (LR register)
+    str  x1, [x0, #0x98]
+
+    ret  lr ; return pointer to context-data (x0)
+
+finish:
+    ; exit code is zero
+    mov  x0, #0
+    ; exit application
+    bl  __exit
+
+
diff --git a/lib/context_switcher/asm/fcontext/make_arm_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/make_arm_aapcs_elf_gas.S
new file mode 100644
index 0000000..98ae64b
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_arm_aapcs_elf_gas.S
@@ -0,0 +1,81 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  v7 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |  v8 |  lr |  pc | FCTX| DATA|                 |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "make_arm_aapcs_elf_gas.S"
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,%function
+.syntax unified
+make_fcontext:
+    @ shift address in A1 to lower 16 byte boundary
+    bic  a1, a1, #15
+
+    @ reserve space for context-data on context-stack
+    sub  a1, a1, #124
+
+    @ third arg of make_fcontext() == address of context-function
+    str  a3, [a1, #104]
+
+    @ compute address of returned transfer_t
+    add  a2, a1, #108
+    mov  a3, a2
+    str  a3, [a1, #64]
+
+    @ compute abs address of label finish
+    adr  a2, finish
+    @ save address of finish as return-address for context-function
+    @ will be entered after context-function returns
+    str  a2, [a1, #100]
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+#endif
+
+    bx  lr @ return pointer to context-data
+
+finish:
+    @ exit code is zero
+    mov  a1, #0
+    @ exit application
+    bl  _exit@PLT
+.size make_fcontext,.-make_fcontext
+
+@ Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_arm_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/make_arm_aapcs_macho_gas.S
new file mode 100644
index 0000000..c909ae9
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_arm_aapcs_macho_gas.S
@@ -0,0 +1,71 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | sjlj|hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |  v7 |  v8 |  lr |  pc | FCTX| DATA|           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _make_fcontext
+.align 2
+_make_fcontext:
+    @ shift address in A1 to lower 16 byte boundary
+    bic  a1, a1, #15
+
+    @ reserve space for context-data on context-stack
+    sub  a1, a1, #124
+
+    @ third arg of make_fcontext() == address of context-function
+    str  a3, [a1, #108]
+
+    @ compute address of returned transfer_t
+    add  a2, a1, #112
+    mov  a3, a2
+    str  a3, [a1, #68]
+
+    @ compute abs address of label finish
+    adr  a2, finish
+    @ save address of finish as return-address for context-function
+    @ will be entered after context-function returns
+    str  a2, [a1, #104]
+
+    bx  lr @ return pointer to context-data
+
+finish:
+    @ exit code is zero
+    mov  a1, #0
+    @ exit application
+    bl  __exit
diff --git a/lib/context_switcher/asm/fcontext/make_arm_aapcs_pe_armasm.asm b/lib/context_switcher/asm/fcontext/make_arm_aapcs_pe_armasm.asm
new file mode 100644
index 0000000..27cbfb0
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_arm_aapcs_pe_armasm.asm
@@ -0,0 +1,77 @@
+;/*
+;            Copyright Oliver Kowalke 2009.
+;   Distributed under the Boost Software License, Version 1.0.
+;      (See accompanying file LICENSE_1_0.txt or copy at
+;          http://www.boost.org/LICENSE_1_0.txt)
+;*/
+
+; *******************************************************
+; *                                                     *
+; *  -------------------------------------------------  *
+; *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+; *  -------------------------------------------------  *
+; *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+; *  -------------------------------------------------  *
+; *  |deall|limit| base|hiddn|  v1 |  v2 |  v3 |  v4 |  *
+; *  -------------------------------------------------  *
+; *  -------------------------------------------------  *
+; *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+; *  -------------------------------------------------  *
+; *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+; *  -------------------------------------------------  *
+; *  |  v5 |  v6 |  v7 |  v8 |  lr |  pc | FCTX| DATA|  *
+; *  -------------------------------------------------  *
+; *                                                     *
+; *******************************************************
+
+
+    AREA |.text|, CODE
+    ALIGN 4
+    EXPORT make_fcontext
+    IMPORT _exit
+
+make_fcontext PROC
+    ; first arg of make_fcontext() == top of context-stack
+    ; save top of context-stack (base) A4
+    mov  a4, a1
+
+    ; shift address in A1 to lower 16 byte boundary
+    bic  a1, a1, #0x0f
+
+    ; reserve space for context-data on context-stack
+    sub  a1, a1, #0x48
+
+    ; save top address of context_stack as 'base'
+    str  a4, [a1, #0x8]
+    ; second arg of make_fcontext() == size of context-stack
+    ; compute bottom address of context-stack (limit)
+    sub  a4, a4, a2
+    ; save bottom address of context-stack as 'limit'
+    str  a4, [a1, #0x4]
+    ; save bottom address of context-stack as 'dealloction stack'
+    str  a4, [a1, #0x0]
+
+    ; third arg of make_fcontext() == address of context-function
+    str  a3, [a1, #0x34]
+
+    ; compute address of returned transfer_t
+    add  a2, a1, #0x38
+    mov  a3, a2
+    str  a3, [a1, #0xc]
+
+    ; compute abs address of label finish
+    adr  a2, finish
+    ; save address of finish as return-address for context-function
+    ; will be entered after context-function returns
+    str  a2, [a1, #0x30]
+
+    bx  lr ; return pointer to context-data
+
+finish
+    ; exit code is zero
+    mov  a1, #0
+    ; exit application
+    bl  _exit
+
+    ENDP
+    END
diff --git a/lib/context_switcher/asm/fcontext/make_combined_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_combined_sysv_macho_gas.S
new file mode 100644
index 0000000..727e904
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_combined_sysv_macho_gas.S
@@ -0,0 +1,20 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "make_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "make_x86_64_sysv_macho_gas.S"
+#elif defined(__ppc__)
+    #include "make_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "make_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/make_i386_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/make_i386_ms_pe_gas.asm
new file mode 100644
index 0000000..10277bb
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_i386_ms_pe_gas.asm
@@ -0,0 +1,153 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+*  --------------------------------------------------------------------------------- *
+*  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    | *
+*  --------------------------------------------------------------------------------- *
+*  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  | *
+*  --------------------------------------------------------------------------------- *
+*  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   | *
+*  --------------------------------------------------------------------------------- *
+*  --------------------------------------------------------------------------------- *
+*  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   | *
+*  --------------------------------------------------------------------------------- *
+*  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  | *
+*  --------------------------------------------------------------------------------- *
+*  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR| *
+*  --------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"make_i386_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+
+/* mark as using no unregistered SEH handlers */
+.globl	@feat.00
+.def	@feat.00;	.scl	3;	.type	0;	.endef
+.set    @feat.00,   1
+
+.globl	_make_fcontext
+.def	_make_fcontext;	.scl	2;	.type	32;	.endef
+_make_fcontext:
+    /* first arg of make_fcontext() == top of context-stack */
+    movl  0x04(%esp), %eax
+
+    /* reserve space for first argument of context-function */
+    /* EAX might already point to a 16byte border */
+    leal  -0x8(%eax), %eax
+
+    /* shift address in EAX to lower 16 byte boundary */
+    andl  $-16, %eax
+
+    /* reserve space for context-data on context-stack */
+    /* size for fc_mxcsr .. EIP + return-address for context-function */
+    /* on context-function entry: (ESP -0x4) % 8 == 0 */
+    /* additional space is required for SEH */
+    leal  -0x40(%eax), %eax
+
+    /* save MMX control- and status-word */
+    stmxcsr  (%eax)
+    /* save x87 control-word */
+    fnstcw  0x4(%eax)
+
+    /* first arg of make_fcontext() == top of context-stack */
+    movl  0x4(%esp), %ecx
+    /* save top address of context stack as 'base' */
+    movl  %ecx, 0x14(%eax)
+    /* second arg of make_fcontext() == size of context-stack */
+    movl  0x8(%esp), %edx
+    /* negate stack size for LEA instruction (== substraction) */
+    negl  %edx
+    /* compute bottom address of context stack (limit) */
+    leal  (%ecx,%edx), %ecx
+    /* save bottom address of context-stack as 'limit' */
+    movl  %ecx, 0x10(%eax)
+    /* save bottom address of context-stack as 'dealloction stack' */
+    movl  %ecx, 0xc(%eax)
+	/* set fiber-storage to zero */
+	xorl  %ecx, %ecx
+    movl  %ecx, 0x8(%eax)
+
+    /* third arg of make_fcontext() == address of context-function */
+    /* stored in EBX */
+    movl  0xc(%esp), %ecx
+    movl  %ecx, 0x24(%eax)
+
+    /* compute abs address of label trampoline */
+    movl  $trampoline, %ecx
+    /* save address of trampoline as return-address for context-function */
+    /* will be entered after calling jump_fcontext() first time */
+    movl  %ecx, 0x2c(%eax)
+
+    /* compute abs address of label finish */
+    movl  $finish, %ecx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movl  %ecx, 0x28(%eax)
+
+    /* traverse current seh chain to get the last exception handler installed by Windows */
+    /* note that on Windows Server 2008 and 2008 R2, SEHOP is activated by default */
+    /* the exception handler chain is tested for the presence of ntdll.dll!FinalExceptionHandler */
+    /* at its end by RaiseException all seh andlers are disregarded if not present and the */
+    /* program is aborted */
+    /* load NT_TIB into ECX */
+    movl  %fs:(0x0), %ecx
+
+walk:
+    /* load 'next' member of current SEH into EDX */
+    movl  (%ecx), %edx
+    /* test if 'next' of current SEH is last (== 0xffffffff) */
+    incl  %edx
+    jz  found
+    decl  %edx
+    /* exchange content; ECX contains address of next SEH */
+    xchgl  %ecx, %edx
+    /* inspect next SEH */
+    jmp  walk
+
+found:
+    /* load 'handler' member of SEH == address of last SEH handler installed by Windows */
+    movl  0x04(%ecx), %ecx
+    /* save address in ECX as SEH handler for context */
+    movl  %ecx, 0x3c(%eax)
+    /* set ECX to -1 */
+    movl  $0xffffffff, %ecx
+    /* save ECX as next SEH item */
+    movl  %ecx, 0x38(%eax)
+    /* load address of next SEH item */
+    leal  0x38(%eax), %ecx
+    /* save next SEH */
+    movl  %ecx, 0x18(%eax)
+
+    /* return pointer to context-data */
+    ret
+
+trampoline:
+    /* move transport_t for entering context-function */
+    /* FCTX == EAX, DATA == EDX */
+    movl  %eax, (%esp)
+    movl  %edx, 0x4(%esp)
+    /* label finish as return-address */
+    pushl %ebp
+    /* jump to context-function */
+    jmp  *%ebx
+
+finish:
+    /* ESP points to same address as ESP on entry of context function + 0x4 */
+    xorl  %eax, %eax
+    /* exit code is zero */
+    movl  %eax, (%esp)
+    /* exit application */
+    call  __exit
+    hlt
+
+.def	__exit;	.scl	2;	.type	32;	.endef  /* standard C library function */
+
+.section .drectve
+.ascii " -export:\"_make_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/make_i386_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/make_i386_ms_pe_masm.asm
new file mode 100644
index 0000000..5246465
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_i386_ms_pe_masm.asm
@@ -0,0 +1,140 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ---------------------------------------------------------------------------------
+;  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    |
+;  ---------------------------------------------------------------------------------
+;  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  |
+;  ---------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   |
+;  ---------------------------------------------------------------------------------
+;  ---------------------------------------------------------------------------------
+;  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   |
+;  ---------------------------------------------------------------------------------
+;  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  |
+;  ---------------------------------------------------------------------------------
+;  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR|
+;  ---------------------------------------------------------------------------------
+
+.386
+.XMM
+.model flat, c
+; standard C library function
+_exit PROTO, value:SDWORD
+.code
+
+make_fcontext PROC BOOST_CONTEXT_EXPORT
+    ; first arg of make_fcontext() == top of context-stack
+    mov  eax, [esp+04h]
+
+    ; reserve space for first argument of context-function
+    ; EAX might already point to a 16byte border
+    lea  eax, [eax-08h]
+
+    ; shift address in EAX to lower 16 byte boundary
+    and  eax, -16
+
+    ; reserve space for context-data on context-stack
+    ; on context-function entry: (ESP -0x4) % 8 == 0
+    ; additional space is required for SEH
+    lea  eax, [eax-040h]
+
+    ; save MMX control- and status-word
+    stmxcsr  [eax]
+    ; save x87 control-word
+    fnstcw  [eax+04h]
+
+    ; first arg of make_fcontext() == top of context-stack
+    mov  ecx, [esp+04h]
+    ; save top address of context stack as 'base'
+    mov  [eax+014h], ecx
+    ; second arg of make_fcontext() == size of context-stack
+    mov  edx, [esp+08h]
+    ; negate stack size for LEA instruction (== substraction)
+    neg  edx
+    ; compute bottom address of context stack (limit)
+    lea  ecx, [ecx+edx]
+    ; save bottom address of context-stack as 'limit'
+    mov  [eax+010h], ecx
+    ; save bottom address of context-stack as 'dealloction stack'
+    mov  [eax+0ch], ecx
+	; set fiber-storage to zero
+	xor  ecx, ecx
+    mov  [eax+08h], ecx
+
+    ; third arg of make_fcontext() == address of context-function
+    ; stored in EBX
+    mov  ecx, [esp+0ch]
+    mov  [eax+024h], ecx
+
+    ; compute abs address of label trampoline
+    mov  ecx, trampoline
+    ; save address of trampoline as return-address for context-function
+    ; will be entered after calling jump_fcontext() first time
+    mov  [eax+02ch], ecx
+
+    ; compute abs address of label finish
+    mov  ecx, finish
+    ; save address of finish as return-address for context-function in EBP
+    ; will be entered after context-function returns
+    mov  [eax+028h], ecx
+
+    ; traverse current seh chain to get the last exception handler installed by Windows
+    ; note that on Windows Server 2008 and 2008 R2, SEHOP is activated by default
+    ; the exception handler chain is tested for the presence of ntdll.dll!FinalExceptionHandler
+    ; at its end by RaiseException all seh-handlers are disregarded if not present and the
+    ; program is aborted
+    assume  fs:nothing
+    ; load NT_TIB into ECX
+    mov  ecx, fs:[0h]
+    assume  fs:error
+
+walk:
+    ; load 'next' member of current SEH into EDX
+    mov  edx, [ecx]
+    ; test if 'next' of current SEH is last (== 0xffffffff)
+    inc  edx
+    jz  found
+    dec  edx
+    ; exchange content; ECX contains address of next SEH
+    xchg edx, ecx
+    ; inspect next SEH
+    jmp  walk
+
+found:
+    ; load 'handler' member of SEH == address of last SEH handler installed by Windows
+    mov  ecx, [ecx+04h]
+    ; save address in ECX as SEH handler for context
+    mov  [eax+03ch], ecx
+    ; set ECX to -1
+    mov  ecx, 0ffffffffh
+    ; save ECX as next SEH item
+    mov  [eax+038h], ecx
+    ; load address of next SEH item
+    lea  ecx, [eax+038h]
+    ; save next SEH
+    mov  [eax+018h], ecx
+
+    ret ; return pointer to context-data
+
+trampoline:
+    ; move transport_t for entering context-function
+    ; FCTX == EAX, DATA == EDX
+    mov  [esp], eax
+    mov  [esp+04h], edx
+    push ebp
+    ; jump to context-function
+    jmp ebx
+
+finish:
+    ; exit code is zero
+    xor  eax, eax
+    mov  [esp], eax
+    ; exit application
+    call  _exit
+    hlt
+make_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/make_i386_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_i386_sysv_elf_gas.S
new file mode 100644
index 0000000..b76de26
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_i386_sysv_elf_gas.S
@@ -0,0 +1,107 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |  hidden |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    to   |   data  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "make_i386_sysv_elf_gas.S"
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,@function
+make_fcontext:
+    /* first arg of make_fcontext() == top of context-stack */
+    movl  0x4(%esp), %eax
+
+    /* reserve space for first argument of context-function
+       eax might already point to a 16byte border */
+    leal  -0x8(%eax), %eax
+
+    /* shift address in EAX to lower 16 byte boundary */
+    andl  $-16, %eax
+
+    /* reserve space for context-data on context-stack */
+    leal  -0x28(%eax), %eax
+
+    /* third arg of make_fcontext() == address of context-function */
+    /* stored in EBX */
+    movl  0xc(%esp), %ecx
+    movl  %ecx, 0x10(%eax)
+
+    /* save MMX control- and status-word */
+    stmxcsr (%eax)
+    /* save x87 control-word */
+    fnstcw  0x4(%eax)
+
+    /* return transport_t */
+    /* FCTX == EDI, DATA == ESI */
+    leal  0x8(%eax), %ecx
+    movl  %ecx, 0x1c(%eax)
+
+    /* compute abs address of label trampoline */
+    call  1f
+    /* address of trampoline 1 */
+1:  popl  %ecx
+    /* compute abs address of label trampoline */
+    addl  $trampoline-1b, %ecx
+    /* save address of trampoline as return address */
+    /* will be entered after calling jump_fcontext() first time */
+    movl  %ecx, 0x18(%eax)
+
+    /* compute abs address of label finish */
+    call  2f
+    /* address of label 2 */
+2:  popl  %ecx
+    /* compute abs address of label finish */
+    addl  $finish-2b, %ecx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movl  %ecx, 0x14(%eax) 
+
+    ret /* return pointer to context-data */
+
+trampoline:
+    /* move transport_t for entering context-function */
+    movl  %edi, (%esp)
+    movl  %esi, 0x4(%esp)
+    pushl %ebp
+    /* jump to context-function */
+    jmp *%ebx
+
+finish:
+    call  3f
+    /* address of label 3 */
+3:  popl  %ebx
+    /* compute address of GOT and store it in EBX */
+    addl  $_GLOBAL_OFFSET_TABLE_+[.-3b], %ebx
+
+    /* exit code is zero */
+    xorl  %eax, %eax
+    movl  %eax, (%esp)
+    /* exit application */
+    call  _exit@PLT
+    hlt
+.size make_fcontext,.-make_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_i386_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_i386_sysv_macho_gas.S
new file mode 100644
index 0000000..fdcdb7c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_i386_sysv_macho_gas.S
@@ -0,0 +1,90 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |    to   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   data  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _make_fcontext
+.align 2
+_make_fcontext:
+    /* first arg of make_fcontext() == top of context-stack */
+    movl  0x4(%esp), %eax
+
+    /* reserve space for first argument of context-function
+       eax might already point to a 16byte border */
+    leal  -0x8(%eax), %eax
+
+    /* shift address in EAX to lower 16 byte boundary */
+    andl  $-16, %eax
+
+    /* reserve space for context-data on context-stack */
+    leal  -0x2c(%eax), %eax
+
+    /* third arg of make_fcontext() == address of context-function */
+    /* stored in EBX */
+    movl  0xc(%esp), %ecx
+    movl  %ecx, 0x10(%eax)
+
+    /* save MMX control- and status-word */
+    stmxcsr (%eax)
+    /* save x87 control-word */
+    fnstcw  0x4(%eax)
+
+    /* compute abs address of label trampoline */
+    call  1f
+    /* address of trampoline 1 */
+1:  popl  %ecx
+    /* compute abs address of label trampoline */
+    addl  $trampoline-1b, %ecx
+    /* save address of trampoline as return address */
+    /* will be entered after calling jump_fcontext() first time */
+    movl  %ecx, 0x18(%eax)
+
+    /* compute abs address of label finish */
+    call  2f
+    /* address of label 2 */
+2:  popl  %ecx
+    /* compute abs address of label finish */
+    addl  $finish-2b, %ecx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movl  %ecx, 0x14(%eax) 
+
+    ret /* return pointer to context-data */
+
+trampoline:
+    /* move transport_t for entering context-function */
+    movl  %eax, (%esp)
+    movl  %edx, 0x4(%esp)
+    pushl %ebp
+    /* jump to context-function */
+    jmp *%ebx
+
+finish:
+    /* exit code is zero */
+    xorl  %eax, %eax
+    movl  %eax, (%esp)
+    /* exit application */
+    call  __exit
+    hlt
diff --git a/lib/context_switcher/asm/fcontext/make_i386_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_i386_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..e364b2d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_i386_x86_64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "make_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "make_x86_64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/make_mips32_o32_elf_gas.S b/lib/context_switcher/asm/fcontext/make_mips32_o32_elf_gas.S
new file mode 100644
index 0000000..4e11e3d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_mips32_o32_elf_gas.S
@@ -0,0 +1,97 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F20    |    F22    |    F24    |    F26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F30    |  S0 |  S1 |  S2 |  S3 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |  S4 |  S5 |  S6 |  S7 |  FP |hiddn|  RA |  PC |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |       ABI ARGS        |  GP | FCTX| DATA|     |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "make_mips32_o32_elf_gas.S"
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,@function
+.ent make_fcontext
+make_fcontext:
+#ifdef __PIC__
+.set    noreorder
+.cpload $t9
+.set    reorder
+#endif
+    # shift address in A0 to lower 16 byte boundary
+    li $v1, -16 # 0xfffffffffffffff0
+    and $v0, $v1, $a0
+
+    # reserve space for context-data on context-stack
+    #  includes an extra 32 bytes for:
+    #  - 16-byte incoming argument area required by mips ABI used when
+    #    jump_context calls the initial function
+    #  - 4 bytes to save our GP register used in finish
+    #  - 8 bytes to as space for transfer_t returned to finish
+    #  - 4 bytes for alignment
+    addiu $v0, $v0, -128
+
+    # third arg of make_fcontext() == address of context-function
+    sw  $a2, 92($v0)
+    # save global pointer in context-data
+    sw  $gp, 112($v0)
+
+    # compute address of returned transfer_t
+    addiu $t0, $v0, 116
+    sw  $t0, 84($v0)
+
+    # compute abs address of label finish
+    la  $t9, finish
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    sw  $t9, 88($v0)
+
+    jr  $ra # return pointer to context-data
+
+finish:
+    # reload our gp register (needed for la)
+    lw $gp, 16($sp)
+
+    # call _exit(0)
+    #  the previous function should have left the 16 bytes incoming argument
+    #  area on the stack which we reuse for calling _exit
+    la $t9, _exit
+    move $a0, $zero
+    jr $t9
+.end make_fcontext
+.size make_fcontext, .-make_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_mips64_n64_elf_gas.S b/lib/context_switcher/asm/fcontext/make_mips64_n64_elf_gas.S
new file mode 100644
index 0000000..7bb30b1
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_mips64_n64_elf_gas.S
@@ -0,0 +1,96 @@
+/*
+            Copyright Jiaxun Yang 2018.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    F24    |    F25    |    F26    |    F27    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F29    |    F30    |    F31    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    FP     |    GP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "make_mips64_n64_elf_gas.S"
+.text
+.globl make_fcontext
+.align 3
+.type make_fcontext,@function
+.ent make_fcontext
+make_fcontext:
+#ifdef __PIC__
+.set    noreorder
+.cpload $t9
+.set    reorder
+#endif
+    # shift address in A0 to lower 16 byte boundary
+    li $v1, 0xfffffffffffffff0
+    and $v0, $v1, $a0
+
+    # reserve space for context-data on context-stack
+    daddiu $v0, $v0, -160
+
+    # third arg of make_fcontext() == address of context-function
+    sd  $a2, 152($v0)
+    # save global pointer in context-data
+    sd  $gp, 136($v0)
+
+    # psudo instruction compute abs address of label finish based on GP
+    dla  $t9, finish
+
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    sd  $t9, 144($v0)
+
+    jr  $ra # return pointer to context-data
+
+finish:
+    # reload our gp register (needed for la)
+    daddiu $t0, $sp, -160
+    ld $gp, 136($t0)
+
+    # call _exit(0)
+    #  the previous function should have left the 16 bytes incoming argument
+    #  area on the stack which we reuse for calling _exit
+    dla $t9, _exit
+    move $a0, $zero
+    jr $t9
+.end make_fcontext
+.size make_fcontext, .-make_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_ppc32_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_ppc32_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..52e7220
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc32_ppc64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__ppc__)
+    #include "make_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "make_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/make_ppc32_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_elf_gas.S
new file mode 100644
index 0000000..9616c4c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_elf_gas.S
@@ -0,0 +1,146 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |bchai|hiddn|   fpscr   |  PC |  CR | R14 | R15 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  | R16 | R17 | R18 | R19 | R20 | R21 | R22 | R23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  | R24 | R25 | R26 | R27 | R28 | R29 | R30 | R31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  ------------------------|------------              *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 |              *
+ *  ------------------------|------------              *
+ *  |    F30    |    F31    |bchai|  LR |              *
+ *  ------------------------|------------              *
+ *                                                     *
+ *******************************************************/
+
+.file "make_ppc32_sysv_elf_gas.S"
+.text
+.globl make_fcontext
+.align 2
+.type make_fcontext,@function
+make_fcontext:
+    # save return address into R6
+    mflr  %r6
+
+    # first arg of make_fcontext() == top address of context-function
+    # shift address in R3 to lower 16 byte boundary
+    clrrwi  %r3, %r3, 4
+
+    # reserve space on context-stack, including 16 bytes of linkage
+    # and parameter area + 240 bytes of context-data (R1 % 16 == 0)
+    subi  %r3, %r3, 16 + 240
+
+    # third arg of make_fcontext() == address of context-function
+#ifdef __linux__
+    # save context-function as PC
+    stw  %r5, 16(%r3)
+#else
+    # save context-function for trampoline
+    stw  %r5, 248(%r3)
+#endif
+
+    # set back-chain to zero
+    li   %r0, 0
+    stw  %r0, 240(%r3)
+
+    # copy FPSCR to new context
+    mffs  %f0
+    stfd  %f0, 8(%r3)
+
+#ifdef __linux__
+    # set hidden pointer for returning transfer_t
+    la    %r0, 248(%r3)
+    stw   %r0, 4(%r3)
+#endif
+
+    # load address of label 1 into R4
+    bl  1f
+1:  mflr  %r4
+#ifndef __linux__
+    # compute abs address of trampoline, use as PC
+    addi  %r7, %r4, trampoline - 1b
+    stw   %r7, 16(%r3)
+#endif
+    # compute abs address of label finish
+    addi  %r4, %r4, finish - 1b
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    stw  %r4, 244(%r3)
+
+    # restore return address from R6
+    mtlr  %r6
+
+    blr  # return pointer to context-data
+
+#ifndef __linux__
+trampoline:
+    # On systems other than Linux, jump_fcontext is returning the
+    # transfer_t in R3:R4, but we need to pass transfer_t * R3 to
+    # our context-function.
+    lwz   %r0, 8(%r1)   # address of context-function
+    mtctr %r0
+    stw   %r3, 8(%r1)
+    stw   %r4, 12(%r1)
+    la    %r3, 8(%r1)   # address of transfer_t
+    bctr
+#endif
+
+finish:
+    # Use the secure PLT for _exit(0).  If we use the insecure BSS PLT
+    # here, then the linker may use the insecure BSS PLT even if the
+    # C++ compiler wanted the secure PLT.
+
+    # set R30 for secure PLT, large model
+    bl     2f
+2:  mflr   %r30
+    addis  %r30, %r30, .Ltoc - 2b@ha
+    addi   %r30, %r30, .Ltoc - 2b@l
+
+    # call _exit(0) with special addend 0x8000 for large model
+    li  %r3, 0
+    bl  _exit + 0x8000@plt
+.size make_fcontext, .-make_fcontext
+
+/* Provide the GOT pointer for secure PLT, large model. */
+.section .got2,"aw"
+.Ltoc = . + 0x8000
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_ppc32_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_macho_gas.S
new file mode 100644
index 0000000..8f35eff
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_macho_gas.S
@@ -0,0 +1,137 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _make_fcontext
+.align 2
+_make_fcontext:
+    # save return address into R6
+    mflr  r6
+
+    # first arg of make_fcontext() == top address of context-function
+    # shift address in R3 to lower 16 byte boundary
+    clrrwi  r3, r3, 4
+
+    # reserve space for context-data on context-stack
+    # including 64 byte of linkage + parameter area (R1  16 == 0)
+    subi  r3, r3, 336
+
+    # third arg of make_fcontext() == address of context-function
+    stw  r5, 240(r3)
+
+    # set back-chain to zero
+    li   r0, 0
+    stw  r0, 244(r3)
+
+    mffs  f0  # load FPSCR
+    stfd  f0, 144(r3)  # save FPSCR
+
+    # compute address of returned transfer_t
+    addi  r0, r3, 252
+    mr    r4, r0 
+    stw   r4, 228(r3) 
+
+    # load LR
+    mflr  r0
+    # jump to label 1
+    bl  1f
+1:
+    # load LR into R4
+    mflr  r4
+    # compute abs address of label finish
+    addi  r4, r4, finish - 1b
+    # restore LR
+    mtlr  r0
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    stw  r4, 236(r3)
+
+    # restore return address from R6
+    mtlr  r6
+
+    blr  # return pointer to context-data
+
+finish:
+    # save return address into R0
+    mflr  r0
+    # save return address on stack, set up stack frame
+    stw  r0, 4(r1)
+    # allocate stack space, R1  16 == 0
+    stwu  r1, -16(r1)
+
+    # exit code is zero
+    li  r3, 0
+    # exit application
+    bl  _exit@plt
diff --git a/lib/context_switcher/asm/fcontext/make_ppc32_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_xcoff_gas.S
new file mode 100644
index 0000000..f257258
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc32_sysv_xcoff_gas.S
@@ -0,0 +1,138 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+	.globl	make_fcontext[DS]
+	.globl .make_fcontext[PR]
+	.align 2 
+	.csect  make_fcontext[DS]
+make_fcontext:
+	.long .make_fcontext[PR]
+	.csect .make_fcontext[PR], 3
+#.make_fcontext:
+    # save return address into R6
+    mflr  6
+
+    # first arg of make_fcontext() == top address of context-function
+    # shift address in R3 to lower 16 byte boundary
+    clrrwi  3, 3, 4
+
+    # reserve space for context-data on context-stack
+    # including 64 byte of linkage + parameter area (R1 % 16 == 0)
+    subi  3, 3, 336
+
+    # third arg of make_fcontext() == address of context-function
+    stw  5, 240(3)
+
+    # set back-chain to zero
+    li   0, 0
+    stw  0, 244(3)
+
+    # compute address of returned transfer_t
+    addi  0, 3, 252
+    mr    4, 0 
+    stw   4, 228(3) 
+
+    # load LR
+    mflr  0
+    # jump to label 1
+    bl  .Label
+.Label:
+    # load LR into R4
+    mflr  4
+    # compute abs address of label .L_finish
+    addi  4, 4, .L_finish - .Label 
+    # restore LR
+    mtlr  0
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    stw  4, 236(3)
+
+    # restore return address from R6
+    mtlr  6
+
+    blr  # return pointer to context-data
+
+.L_finish:
+    # save return address into R0
+    mflr  0
+    # save return address on stack, set up stack frame
+    stw  0, 4(1)
+    # allocate stack space, R1 % 16 == 0
+    stwu  1, -16(1)
+
+    # exit code is zero
+    li  3, 0
+    # exit application
+    bl  ._exit
+    nop
diff --git a/lib/context_switcher/asm/fcontext/make_ppc64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_elf_gas.S
new file mode 100644
index 0000000..c4d7ee5
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_elf_gas.S
@@ -0,0 +1,177 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "make_ppc64_sysv_elf_gas.S"
+.globl make_fcontext
+#if _CALL_ELF == 2
+	.text
+	.align 2
+make_fcontext:
+	addis	%r2, %r12, .TOC.-make_fcontext@ha
+	addi	%r2, %r2, .TOC.-make_fcontext@l
+	.localentry make_fcontext, . - make_fcontext
+#else
+	.section ".opd","aw"
+	.align 3
+make_fcontext:
+# ifdef _CALL_LINUX
+	.quad	.L.make_fcontext,.TOC.@tocbase,0
+	.type	make_fcontext,@function
+	.text
+	.align 2
+.L.make_fcontext:
+# else
+	.hidden	.make_fcontext
+	.globl	.make_fcontext
+	.quad	.make_fcontext,.TOC.@tocbase,0
+	.size	make_fcontext,24
+	.type	.make_fcontext,@function
+	.text
+	.align 2
+.make_fcontext:
+# endif
+#endif
+    # save return address into R6
+    mflr  %r6
+
+    # first arg of make_fcontext() == top address of context-stack
+    # shift address in R3 to lower 16 byte boundary
+    clrrdi  %r3, %r3, 4
+
+    # reserve space for context-data on context-stack
+    # including 64 byte of linkage + parameter area (R1 % 16 == 0)
+    subi  %r3, %r3, 248
+
+    # third arg of make_fcontext() == address of context-function
+    # entry point (ELFv2) or descriptor (ELFv1)
+#if _CALL_ELF == 2
+    # save address of context-function entry point
+    std  %r5, 176(%r3)
+#else
+    # save address of context-function entry point
+    ld   %r4, 0(%r5)
+    std  %r4, 176(%r3)
+    # save TOC of context-function
+    ld   %r4, 8(%r5)
+    std  %r4, 0(%r3)
+#endif
+
+    # set back-chain to zero
+    li   %r0, 0
+    std  %r0, 184(%r3)
+
+#if _CALL_ELF != 2
+    # zero in r3 indicates first jump to context-function
+    std  %r0, 152(%r3)
+#endif
+
+    # load LR
+    mflr  %r0
+    # jump to label 1
+    bl  1f
+1:
+    # load LR into R4
+    mflr  %r4
+    # compute abs address of label finish
+    addi  %r4, %r4, finish - 1b
+    # restore LR
+    mtlr  %r0
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    std  %r4, 168(%r3)
+
+    # restore return address from R6
+    mtlr  %r6
+
+    blr  # return pointer to context-data
+
+finish:
+    # save return address into R0
+    mflr  %r0
+    # save return address on stack, set up stack frame
+    std  %r0, 8(%r1)
+    # allocate stack space, R1 % 16 == 0
+    stdu  %r1, -32(%r1)
+
+    # exit code is zero
+    li  %r3, 0
+    # exit application
+    bl  _exit
+    nop
+#if _CALL_ELF == 2
+	.size make_fcontext, .-make_fcontext
+#else
+# ifdef _CALL_LINUX
+	.size .make_fcontext, .-.L.make_fcontext
+# else
+	.size .make_fcontext, .-.make_fcontext
+# endif
+#endif
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..7b947bb
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_macho_gas.S
@@ -0,0 +1,126 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+
+.text
+.globl _make_fcontext
+_make_fcontext:
+    ; save return address into R6
+    mflr  r6
+
+    ; first arg of make_fcontext() == top address of context-function
+    ; shift address in R3 to lower 16 byte boundary
+    clrrwi  r3, r3, 4
+
+    ; reserve space for context-data on context-stack
+    ; including 64 byte of linkage + parameter area (R1  16 == 0)
+    subi  r3, r3, 248
+
+    ; third arg of make_fcontext() == address of context-function
+    stw  r5, 176(r3)
+
+    ; set back-chain to zero
+    li   %r0, 0
+    std  %r0, 184(%r3)
+
+    ; compute address of returned transfer_t
+    addi %r0, %r3, 232
+    mr   %r4, %r0
+    std  %r4, 152(%r3)
+
+    ; load LR
+    mflr  r0
+    ; jump to label 1
+    bl  l1
+l1:
+    ; load LR into R4
+    mflr  r4
+    ; compute abs address of label finish
+    addi  r4, r4, lo16((finish - .) + 4)
+    ; restore LR
+    mtlr  r0
+    ; save address of finish as return-address for context-function
+    ; will be entered after context-function returns
+    std  r4, 168(r3)
+
+    ; restore return address from R6
+    mtlr  r6
+
+    blr  ; return pointer to context-data
+
+finish:
+    ; save return address into R0
+    mflr  r0
+    ; save return address on stack, set up stack frame
+    stw  r0, 8(r1)
+    ; allocate stack space, R1  16 == 0
+    stwu  r1, -32(r1)
+
+    ; set return value to zero
+    li  r3, 0
+    ; exit application
+    bl  __exit
+    nop
diff --git a/lib/context_switcher/asm/fcontext/make_ppc64_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_xcoff_gas.S
new file mode 100644
index 0000000..60ad6b6
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_ppc64_sysv_xcoff_gas.S
@@ -0,0 +1,68 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+	.globl	make_fcontext[DS]
+	.globl .make_fcontext[PR]
+	.align 2 
+	.csect .make_fcontext[PR], 3
+	.globl _make_fcontext
+#._make_fcontext:
+    # save return address into R6
+    mflr  6
+
+    # first arg of make_fcontext() == top address of context-function
+    # shift address in R3 to lower 16 byte boundary
+    clrrwi  3, 3, 4
+
+    # reserve space for context-data on context-stack
+    # including 64 byte of linkage + parameter area (R1 % 16 == 0)
+    subi  3, 3, 248
+
+    # third arg of make_fcontext() == address of context-function
+    stw  5, 176(3)
+
+    # set back-chain to zero
+    li   0, 0
+    std  0, 184(3)
+
+    # compute address of returned transfer_t
+    addi 0, 3, 232
+    mr   4, 0
+    std  4, 152(3)
+
+    # load LR
+    mflr  0
+    # jump to label 1
+    bl  .Label
+.Label:
+    # load LR into R4
+    mflr  4
+    # compute abs address of label .L_finish
+    addi  4, 4, .L_finish - .Label
+    # restore LR
+    mtlr  0
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns
+    stw  4, 168(3)
+
+    # restore return address from R6
+    mtlr  6
+
+    blr  # return pointer to context-data
+
+.L_finish:
+    # save return address into R0
+    mflr  0
+    # save return address on stack, set up stack frame
+    stw  0, 8(1)
+    # allocate stack space, R1 % 16 == 0
+    stwu  1, -32(1)
+
+    # exit code is zero
+    li  3, 0
+    # exit application
+    bl  ._exit
+    nop
diff --git a/lib/context_switcher/asm/fcontext/make_riscv64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_riscv64_sysv_elf_gas.S
new file mode 100644
index 0000000..5322e0f
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_riscv64_sysv_elf_gas.S
@@ -0,0 +1,91 @@
+/*
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    fs0    |    fs1    |    fs2    |    fs3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    fs4    |    fs5    |    fs6    |    fs7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    fs8    |    fs9    |    fs10   |    fs11   |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    s0     |    s1     |    s2     |    s3     |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    s4     |    s5     |    s6     |     s7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |  44 | 45  |  46 | 47  |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac| 0xb0| 0xb4| 0xb8| 0xbc|  *
+ *  -------------------------------------------------  *
+ *  |     s8    |     s9    |    s10    |    s11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 | 51  |     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  | 0xc0| 0xc4| 0xc8| 0xcc|     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  |     ra    |     pc    |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "make_riscv64_sysv_elf_gas.S"
+.text
+.align  1
+.global make_fcontext
+.type   make_fcontext, %function
+make_fcontext:
+    # shift address in a0 (allocated stack) to lower 16 byte boundary
+    andi a0, a0, ~0xF
+
+    # reserve space for context-data on context-stack
+    addi  a0, a0, -0xd0
+
+    # third arg of make_fcontext() == address of context-function
+    # store address as a PC to jump in
+    sd  a2, 0xc8(a0)
+
+    # save address of finish as return-address for context-function
+    # will be entered after context-function returns (RA register)
+    lla  a4, finish
+    sd  a4, 0xc0(a0)
+
+    ret // return pointer to context-data (a0)
+
+finish:
+    # exit code is zero
+    li  a0, 0
+    # exit application
+    tail  _exit@plt
+
+.size   make_fcontext,.-make_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_s390x_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_s390x_sysv_elf_gas.S
new file mode 100644
index 0000000..d02856c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_s390x_sysv_elf_gas.S
@@ -0,0 +1,104 @@
+/*******************************************************
+*                                                     *
+*  -------------------------------------------------  *
+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+*  -------------------------------------------------  *
+*  |     0     |     8     |    16     |     24    |  *
+*  -------------------------------------------------  *
+*  |    R6     |    R7     |    R8     |    R9     |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+*  -------------------------------------------------  *
+*  |     32    |    40     |     48    |     56    |  *
+*  -------------------------------------------------  *
+*  |    R10    |    R11    |     R12   |     R13   |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+*  -------------------------------------------------  *
+*  |     64    |    72     |     80    |     88    |  *
+*  -------------------------------------------------  *
+*  |   R14/LR  |    R15    |     F1    |     F3    |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *
+*  -------------------------------------------------  *
+*  |     96    |    104    |    112    |    120    |  *
+*  -------------------------------------------------  *
+*  |    F5     |    F7     |     PC    |           |  *
+*  -------------------------------------------------  *
+* *****************************************************/
+
+.file  "make_s390x_sysv_elf_gas.S"
+.text
+.align  4 # According to the sample code in the ELF ABI docs
+.global make_fcontext
+.type 	 make_fcontext, @function
+
+#define GR_OFFSET	0
+#define LR_OFFSET	64
+#define SP_OFFSET	72
+#define FP_OFFSET	80
+#define PC_OFFSET	112
+#define L_CTX		120
+#define L_STACKFRAME	120
+
+make_fcontext:
+
+		# make_fcontext takes in 3 arguments
+		# arg1 --> The address where the context needs to be made
+		# arg2 --> The size of the context
+		# arg3 --> The address of the context function
+
+		# According to the ELF ABI, the register R2 holds the first arg.
+		# R2 also acts as the register which holds return value
+		# Register R3 holds the second, R4 the third so on.
+
+		# Shift the address in R2 to a lower 8 byte boundary
+
+		# This is done because according to the ELF ABI Doc, the stack needs
+		# to be 8 byte aligned.
+		# In order to do so, we need to make sure that the address is divisible
+		# by 8. We can check this, by checking if the the last 3 bits of the
+		# address is zero or not. If not AND it with `-8`. 
+
+		# Here we AND the lower 16 bits of the memory address present in the 
+		# R2 with the bits 1111 1111 1111 1000 
+		nill    %r2,0xfff0
+
+		# Reserve space for context-data on context-stack.
+		# This is done by shifting the SP/address by 112 bytes.
+		aghi	%r2,-L_CTX
+
+		# third arg of make_fcontext() == address of the context-function
+		# Store the address as a PC to jump in, whenever we call the 
+		# make_fcontext.
+		stg 	%r4,PC_OFFSET(%r2)
+
+		# Save the address of finish as return-address for context-function
+		# This will be entered after context-function return
+		# The address of finish will be saved in Link register, this register
+		# specifies where we need to jump after the function executes
+		# completely.
+		larl 	%r1,finish
+		stg  	%r1,LR_OFFSET(%r2)
+
+		# Return pointer to context data
+		# R14 acts as the link register
+		# R2 holds the address of the context stack. When we return from the
+		# make_fcontext, R2 is passed back.
+		br 	%r14 
+
+	finish:
+
+		# In finish tasks, you load the exit code and exit the make_fcontext
+		# This is called when the context-function is entirely executed
+
+		lghi 	%r2,0
+		brasl 	%r14,_exit@PLT
+
+.size   make_fcontext,.-make_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
+
diff --git a/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_gas.asm
new file mode 100644
index 0000000..958a2a7
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_gas.asm
@@ -0,0 +1,174 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+* ---------------------------------------------------------------------------------- *
+* |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   | *
+* ---------------------------------------------------------------------------------- *
+* |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  | *
+* ---------------------------------------------------------------------------------- *
+* | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  | *
+* ---------------------------------------------------------------------------------- *
+* |        limit      |         base       |         R12       |         R13       | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  | *
+* ---------------------------------------------------------------------------------- *
+* |        R14        |         R15        |         RDI       |        RSI        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  | *
+* ---------------------------------------------------------------------------------- *
+* |        RBX        |         RBP        |       hidden      |        RIP        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  | *
+* ---------------------------------------------------------------------------------- *
+* |                                   parameter area                               | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  | *
+* ---------------------------------------------------------------------------------- *
+* |       FCTX        |        DATA        |                                       | *
+* ---------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"make_x86_64_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+.globl	make_fcontext
+.def	make_fcontext;	.scl	2;	.type	32;	.endef
+.seh_proc	make_fcontext
+make_fcontext:
+.seh_endprologue
+
+    /* first arg of make_fcontext() == top of context-stack */
+    movq  %rcx, %rax
+
+    /* shift address in RAX to lower 16 byte boundary */
+    /* == pointer to fcontext_t and address of context stack */
+    andq  $-16, %rax
+
+    /* reserve space for context-data on context-stack */
+    /* on context-function entry: (RSP -0x8) % 16 == 0 */
+    leaq  -0x150(%rax), %rax
+
+    /* third arg of make_fcontext() == address of context-function */
+    movq  %r8, 0x100(%rax)
+
+    /* first arg of make_fcontext() == top of context-stack */
+    /* save top address of context stack as 'base' */
+    movq  %rcx, 0xc8(%rax)
+    /* second arg of make_fcontext() == size of context-stack */
+    /* negate stack size for LEA instruction (== substraction) */
+    negq  %rdx
+    /* compute bottom address of context stack (limit) */
+    leaq  (%rcx,%rdx), %rcx
+    /* save bottom address of context stack as 'limit' */
+    movq  %rcx, 0xc0(%rax)
+    /* save address of context stack limit as 'dealloction stack' */
+    movq  %rcx, 0xb8(%rax)
+	/* set fiber-storage to zero */
+    xorq  %rcx, %rcx
+    movq  %rcx, 0xb0(%rax)
+
+	/* save MMX control- and status-word */
+    stmxcsr  0xa0(%rax)
+    /* save x87 control-word */
+    fnstcw   0xa4(%rax)
+
+    /* compute address of transport_t */
+    leaq  0x140(%rax), %rcx
+    /* store address of transport_t in hidden field */
+    movq %rcx, 0x110(%rax)
+
+    /* compute abs address of label trampoline */
+    leaq  trampoline(%rip), %rcx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after jump_fcontext() first time */
+    movq  %rcx, 0x118(%rax)
+
+    /* compute abs address of label finish */
+    leaq  finish(%rip), %rcx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movq  %rcx, 0x108(%rax)
+
+    ret /* return pointer to context-data */
+
+trampoline:
+    /* store return address on stack */
+    /* fix stack alignment */ 
+    pushq %rbp
+    /* jump to context-function */
+    jmp *%rbx
+
+finish:
+    /* 32byte shadow-space for _exit() */
+    andq  $-32, %rsp
+    /* 32byte shadow-space for _exit() are */
+    /* already reserved by make_fcontext() */
+    /* exit code is zero */
+    xorq  %rcx, %rcx
+    /* exit application */
+    call  _exit
+    hlt
+.seh_endproc
+
+.def	_exit;	.scl	2;	.type	32;	.endef  /* standard C library function */
+
+.section .drectve
+.ascii " -export:\"make_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_masm.asm
new file mode 100644
index 0000000..8f6c959
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_x86_64_ms_pe_masm.asm
@@ -0,0 +1,163 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ----------------------------------------------------------------------------------
+;  |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   |
+;  ----------------------------------------------------------------------------------
+;  |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   |
+;  ----------------------------------------------------------------------------------
+;  |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   |
+;  ----------------------------------------------------------------------------------
+;  |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   |
+;  ----------------------------------------------------------------------------------
+;  |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   |
+;  ----------------------------------------------------------------------------------
+;  |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  |
+;  ----------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   |
+;  ----------------------------------------------------------------------------------
+;  |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  |
+;  ----------------------------------------------------------------------------------
+;  |        limit      |         base       |         R12       |         R13       |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  |
+;  ----------------------------------------------------------------------------------
+;  |        R14        |         R15        |         RDI       |        RSI        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   |
+;  ----------------------------------------------------------------------------------
+;  |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  |
+;  ----------------------------------------------------------------------------------
+;  |        RBX        |         RBP        |       hidden      |        RIP        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   |
+;  ----------------------------------------------------------------------------------
+;  |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  |
+;  ----------------------------------------------------------------------------------
+;  |                                   parameter area                               |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   |
+;  ----------------------------------------------------------------------------------
+;  |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  |
+;  ----------------------------------------------------------------------------------
+;  |       FCTX        |        DATA        |                                       |
+;  ----------------------------------------------------------------------------------
+
+; standard C library function
+EXTERN  _exit:PROC
+.code
+
+; generate function table entry in .pdata and unwind information in
+make_fcontext PROC BOOST_CONTEXT_EXPORT FRAME
+    ; .xdata for a function's structured exception handling unwind behavior
+    .endprolog
+
+    ; first arg of make_fcontext() == top of context-stack
+    mov  rax, rcx
+
+    ; shift address in RAX to lower 16 byte boundary
+    ; == pointer to fcontext_t and address of context stack
+    and  rax, -16
+
+    ; reserve space for context-data on context-stack
+    ; on context-function entry: (RSP -0x8) % 16 == 0
+    sub  rax, 0150h
+
+    ; third arg of make_fcontext() == address of context-function
+    ; stored in RBX
+    mov  [rax+0100h], r8
+
+    ; first arg of make_fcontext() == top of context-stack
+    ; save top address of context stack as 'base'
+    mov  [rax+0c8h], rcx
+    ; second arg of make_fcontext() == size of context-stack
+    ; negate stack size for LEA instruction (== substraction)
+    neg  rdx
+    ; compute bottom address of context stack (limit)
+    lea  rcx, [rcx+rdx]
+    ; save bottom address of context stack as 'limit'
+    mov  [rax+0c0h], rcx
+    ; save address of context stack limit as 'dealloction stack'
+    mov  [rax+0b8h], rcx
+	; set fiber-storage to zero
+	xor  rcx, rcx
+    mov  [rax+0b0h], rcx
+
+	; save MMX control- and status-word
+    stmxcsr  [rax+0a0h]
+    ; save x87 control-word
+    fnstcw  [rax+0a4h]
+
+    ; compute address of transport_t
+    lea rcx, [rax+0140h]
+    ; store address of transport_t in hidden field
+    mov [rax+0110h], rcx
+
+    ; compute abs address of label trampoline
+    lea  rcx, trampoline
+    ; save address of trampoline as return-address for context-function
+    ; will be entered after calling jump_fcontext() first time
+    mov  [rax+0118h], rcx
+
+    ; compute abs address of label finish
+    lea  rcx, finish
+    ; save address of finish as return-address for context-function in RBP
+    ; will be entered after context-function returns 
+    mov  [rax+0108h], rcx
+
+    ret ; return pointer to context-data
+
+trampoline:
+    ; store return address on stack
+    ; fix stack alignment
+    push rbp
+    ; jump to context-function
+    jmp rbx
+
+finish:
+    ; exit code is zero
+    xor  rcx, rcx
+    ; exit application
+    call  _exit
+    hlt
+make_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/make_x86_64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/make_x86_64_sysv_elf_gas.S
new file mode 100644
index 0000000..0ef3756
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_x86_64_sysv_elf_gas.S
@@ -0,0 +1,82 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "make_x86_64_sysv_elf_gas.S"
+.text
+.globl make_fcontext
+.type make_fcontext,@function
+.align 16
+make_fcontext:
+    /* first arg of make_fcontext() == top of context-stack */
+    movq  %rdi, %rax
+
+    /* shift address in RAX to lower 16 byte boundary */
+    andq  $-16, %rax
+
+    /* reserve space for context-data on context-stack */
+    /* on context-function entry: (RSP -0x8) % 16 == 0 */
+    leaq  -0x40(%rax), %rax
+
+    /* third arg of make_fcontext() == address of context-function */
+    /* stored in RBX */
+    movq  %rdx, 0x28(%rax)
+
+    /* save MMX control- and status-word */
+    stmxcsr  (%rax)
+    /* save x87 control-word */
+    fnstcw   0x4(%rax)
+
+    /* compute abs address of label trampoline */
+    leaq  trampoline(%rip), %rcx
+    /* save address of trampoline as return-address for context-function */
+    /* will be entered after calling jump_fcontext() first time */
+    movq  %rcx, 0x38(%rax)
+
+    /* compute abs address of label finish */
+    leaq  finish(%rip), %rcx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movq  %rcx, 0x30(%rax)
+
+    ret /* return pointer to context-data */
+
+trampoline:
+    /* store return address on stack */
+    /* fix stack alignment */
+    push %rbp
+    /* jump to context-function */
+    jmp *%rbx
+
+finish:
+    /* exit code is zero */
+    xorq  %rdi, %rdi
+    /* exit application */
+    call  _exit@PLT
+    hlt
+.size make_fcontext,.-make_fcontext
+
+/* Mark that we don't need executable stack. */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/make_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/make_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..5d6c543
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/make_x86_64_sysv_macho_gas.S
@@ -0,0 +1,76 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _make_fcontext
+.align 8
+_make_fcontext:
+    /* first arg of make_fcontext() == top of context-stack */
+    movq  %rdi, %rax
+
+    /* shift address in RAX to lower 16 byte boundary */
+    andq  $-16, %rax
+
+    /* reserve space for context-data on context-stack */
+    /* on context-function entry: (RSP -0x8) % 16 == 0 */
+    leaq  -0x40(%rax), %rax
+
+    /* third arg of make_fcontext() == address of context-function */
+    /* stored in RBX */
+    movq  %rdx, 0x28(%rax)
+
+    /* save MMX control- and status-word */
+    stmxcsr  (%rax)
+    /* save x87 control-word */
+    fnstcw   0x4(%rax)
+
+    /* compute abs address of label trampoline */
+    leaq  trampoline(%rip), %rcx
+    /* save address of trampoline as return-address for context-function */
+    /* will be entered after calling jump_fcontext() first time */
+    movq  %rcx, 0x38(%rax)
+
+    /* compute abs address of label finish */
+    leaq  finish(%rip), %rcx
+    /* save address of finish as return-address for context-function */
+    /* will be entered after context-function returns */
+    movq  %rcx, 0x30(%rax)
+
+    ret /* return pointer to context-data */
+
+trampoline:
+    /* store return address on stack */
+    /* fix stack alignment */
+    push %rbp
+    /* jump to context-function */
+    jmp *%rbx
+
+finish:
+    /* exit code is zero */
+    xorq  %rdi, %rdi
+    /* exit application */
+    call  __exit
+    hlt
diff --git a/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_elf_gas.S
new file mode 100644
index 0000000..665ca5a
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_elf_gas.S
@@ -0,0 +1,113 @@
+/*
+       Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "ontop_arm64_aapcs_elf_gas.S"
+.text
+.align  2
+.global ontop_fcontext
+.type   ontop_fcontext, %function
+ontop_fcontext:
+    # prepare stack for GP + FPU
+    sub  sp, sp, #0xb0
+
+    # save d8 - d15
+    stp  d8,  d9,  [sp, #0x00]
+    stp  d10, d11, [sp, #0x10]
+    stp  d12, d13, [sp, #0x20]
+    stp  d14, d15, [sp, #0x30]
+
+    # save x19-x30
+    stp  x19, x20, [sp, #0x40]
+    stp  x21, x22, [sp, #0x50]
+    stp  x23, x24, [sp, #0x60]
+    stp  x25, x26, [sp, #0x70]
+    stp  x27, x28, [sp, #0x80]
+    stp  x29, x30, [sp, #0x90]
+
+    # save LR as PC
+    str  x30, [sp, #0xa0]
+
+    # store RSP (pointing to context-data) in X5
+    mov  x4, sp
+
+    # restore RSP (pointing to context-data) from X1
+    mov  sp, x0
+
+    # load d8 - d15
+    ldp  d8,  d9,  [sp, #0x00]
+    ldp  d10, d11, [sp, #0x10]
+    ldp  d12, d13, [sp, #0x20]
+    ldp  d14, d15, [sp, #0x30]
+
+    # load x19-x30
+    ldp  x19, x20, [sp, #0x40]
+    ldp  x21, x22, [sp, #0x50]
+    ldp  x23, x24, [sp, #0x60]
+    ldp  x25, x26, [sp, #0x70]
+    ldp  x27, x28, [sp, #0x80]
+    ldp  x29, x30, [sp, #0x90]
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # X0 == FCTX, X1 == DATA
+    mov x0, x4
+
+    # skip pc
+    # restore stack from GP + FPU
+    add  sp, sp, #0xb0
+
+    # jump to ontop-function
+    ret x2
+.size   ontop_fcontext,.-ontop_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_macho_gas.S
new file mode 100644
index 0000000..a387d06
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_arm64_aapcs_macho_gas.S
@@ -0,0 +1,108 @@
+/*
+       Copyright Edward Nevill + Oliver Kowalke 2015
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    d8     |    d9     |    d10    |    d11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    d12    |    d13    |    d14    |    d15    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    x19    |    x20    |    x21    |    x22    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    x23    |    x24    |    x25    |    x26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    x27    |    x28    |    FP     |     LR    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |           |           |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac|           |           |  *
+ *  -------------------------------------------------  *
+ *  |     PC    |   align   |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.global _ontop_fcontext
+.balign 16
+_ontop_fcontext:
+    ; prepare stack for GP + FPU
+    sub  sp, sp, #0xb0
+
+    ; save d8 - d15
+    stp  d8,  d9,  [sp, #0x00]
+    stp  d10, d11, [sp, #0x10]
+    stp  d12, d13, [sp, #0x20]
+    stp  d14, d15, [sp, #0x30]
+
+    ; save x19-x30
+    stp  x19, x20, [sp, #0x40]
+    stp  x21, x22, [sp, #0x50]
+    stp  x23, x24, [sp, #0x60]
+    stp  x25, x26, [sp, #0x70]
+    stp  x27, x28, [sp, #0x80]
+    stp  x29, x30, [sp, #0x90]
+
+    ; save LR as PC
+    str  x30, [sp, #0xa0]
+
+    ; store RSP (pointing to context-data) in X5
+    mov  x4, sp
+
+    ; restore RSP (pointing to context-data) from X1
+    mov  sp, x0
+
+    ; load d8 - d15
+    ldp  d8,  d9,  [sp, #0x00]
+    ldp  d10, d11, [sp, #0x10]
+    ldp  d12, d13, [sp, #0x20]
+    ldp  d14, d15, [sp, #0x30]
+
+    ; load x19-x30
+    ldp  x19, x20, [sp, #0x40]
+    ldp  x21, x22, [sp, #0x50]
+    ldp  x23, x24, [sp, #0x60]
+    ldp  x25, x26, [sp, #0x70]
+    ldp  x27, x28, [sp, #0x80]
+    ldp  x29, x30, [sp, #0x90]
+
+    ; return transfer_t from jump
+    ; pass transfer_t as first arg in context function
+    ; X0 == FCTX, X1 == DATA
+    mov x0, x4
+
+    ; skip pc
+    ; restore stack from GP + FPU
+    add  sp, sp, #0xb0
+
+    ; jump to ontop-function
+    ret x2
diff --git a/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_elf_gas.S
new file mode 100644
index 0000000..59ad5ca
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_elf_gas.S
@@ -0,0 +1,93 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  v7 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |  v8 |  lr |  pc | FCTX| DATA|                 |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "ontop_arm_aapcs_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 2
+.type ontop_fcontext,%function
+.syntax unified
+ontop_fcontext:
+    @ save LR as PC
+    push {lr}
+    @ save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    @ prepare stack for FPU
+    sub  sp, sp, #64
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ save S16-S31
+    vstmia sp, {d8-d15}
+#endif
+
+    @ store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    @ restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+    @ store parent context in A2
+    mov  a2, a1
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ restore S16-S31
+    vldmia  sp, {d8-d15}
+#endif
+    @ prepare stack for FPU
+    add  sp, sp, #64
+
+    @ restore hidden,V1-V8,LR
+    pop {a1,v1-v8,lr}
+
+    @ return transfer_t from jump
+    str  a2, [a1, #0]
+    str  a3, [a1, #4]
+    @ pass transfer_t as first arg in context function
+    @ A1 == hidden, A2 == FCTX, A3 == DATA
+
+    @ skip PC
+    add  sp, sp, #4
+
+    @ jump to ontop-function
+    bx  a4
+.size ontop_fcontext,.-ontop_fcontext
+
+@ Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_macho_gas.S
new file mode 100644
index 0000000..421fcb4
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_macho_gas.S
@@ -0,0 +1,100 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | s16 | s17 | s18 | s19 | s20 | s21 | s22 | s23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  | s24 | s25 | s26 | s27 | s28 | s29 | s30 | s31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  | sjlj|hiddn|  v1 |  v2 |  v3 |  v4 |  v5 |  v6 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |  v7 |  v8 |  lr |  pc | FCTX| DATA|           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _ontop_fcontext
+.align 2
+_ontop_fcontext:
+    @ save LR as PC
+    push {lr}
+    @ save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    @ locate TLS to save/restore SjLj handler
+    mrc  p15, 0, v2, c13, c0, #3
+    bic  v2, v2, #3
+
+    @ load TLS[__PTK_LIBC_DYLD_Unwind_SjLj_Key]
+    ldr  v1, [v2, #8]
+    @ save SjLj handler
+    push  {v1}
+
+    @ prepare stack for FPU
+    sub  sp, sp, #64
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ save S16-S31
+    vstmia sp, {d8-d15}
+#endif
+
+    @ store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    @ restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
+    @ restore S16-S31
+    vldmia  sp, {d8-d15}
+#endif
+    @ prepare stack for FPU
+    add  sp, sp, #64
+
+    @ restore SjLj handler
+    pop  {v1}
+    @ store SjLj handler in TLS
+    str  v1, [v2, #8]
+
+    @ store parent context in A2
+    mov  a2, a1
+
+    @ restore hidden,V1-V8,LR
+    pop {a1,v1-v8,lr}
+
+    @ return transfer_t from jump
+    str  a2, [a1, #0]
+    str  a3, [a1, #4]
+    @ pass transfer_t as first arg in context function
+    @ A1 == hidden, A2 == FCTX, A3 == DATA
+
+    @ skip PC
+    add  sp, sp, #4
+
+    @ jump to ontop-function
+    bx  a4
diff --git a/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_pe_armasm.asm b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_pe_armasm.asm
new file mode 100644
index 0000000..f360a8f
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_arm_aapcs_pe_armasm.asm
@@ -0,0 +1,86 @@
+;/*
+;            Copyright Oliver Kowalke 2009.
+;   Distributed under the Boost Software License, Version 1.0.
+;      (See accompanying file LICENSE_1_0.txt or copy at
+;          http://www.boost.org/LICENSE_1_0.txt)
+;*/
+
+; *******************************************************
+; *                                                     *
+; *  -------------------------------------------------  *
+; *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+; *  -------------------------------------------------  *
+; *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+; *  -------------------------------------------------  *
+; *  |deall|limit| base|hiddn|  v1 |  v2 |  v3 |  v4 |  *
+; *  -------------------------------------------------  *
+; *  -------------------------------------------------  *
+; *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+; *  -------------------------------------------------  *
+; *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+; *  -------------------------------------------------  *
+; *  |  v5 |  v6 |  v7 |  v8 |  lr |  pc | FCTX| DATA|  *
+; *  -------------------------------------------------  *
+; *                                                     *
+; *******************************************************
+
+    AREA |.text|, CODE
+    ALIGN 4
+    EXPORT ontop_fcontext
+
+ontop_fcontext PROC
+    ; save LR as PC
+    push {lr}
+    ; save hidden,V1-V8,LR
+    push {a1,v1-v8,lr}
+
+    ; load TIB to save/restore thread size and limit.
+    ; we do not need preserve CPU flag and can use it's arg register
+    mrc     p15, #0, v1, c13, c0, #2
+
+    ; save current stack base
+    ldr  a1, [v1, #0x04]
+    push {a1}
+    ; save current stack limit
+    ldr  a1, [v1, #0x08]
+    push {a1}
+    ; save current deallocation stack
+    ldr  a1, [v1, #0xe0c]
+    push {a1}
+
+    ; store RSP (pointing to context-data) in A1
+    mov  a1, sp
+
+    ; restore RSP (pointing to context-data) from A2
+    mov  sp, a2
+
+    ; restore stack base
+    pop  {a1}
+    str  a1, [v1, #0x04]
+    ; restore stack limit
+    pop  {a1}
+    str  a1, [v1, #0x08]
+    ; restore deallocation stack
+    pop  {a1}
+    str  a1, [v1, #0xe0c]
+
+    ; store parent context in A2
+    mov  a2, a1
+
+    ; restore hidden,V1-V8,LR
+    pop {a1,v1-v8,lr}
+
+    ; return transfer_t from jump
+    str  a2, [a1, #0]
+    str  a3, [a1, #4]
+    ; pass transfer_t as first arg in context function
+    ; A1 == hidden, A2 == FCTX, A3 == DATA
+
+    ; skip PC
+    add  sp, sp, #4
+
+    ; jump to ontop-function
+    bx  a4
+
+    ENDP
+    END
diff --git a/lib/context_switcher/asm/fcontext/ontop_combined_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_combined_sysv_macho_gas.S
new file mode 100644
index 0000000..20cbeb9
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_combined_sysv_macho_gas.S
@@ -0,0 +1,20 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "ontop_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "ontop_x86_64_sysv_macho_gas.S"
+#elif defined(__ppc__)
+    #include "ontop_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "ontop_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_gas.asm
new file mode 100644
index 0000000..c23e18a
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_gas.asm
@@ -0,0 +1,131 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+*  --------------------------------------------------------------------------------- *
+*  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    | *
+*  --------------------------------------------------------------------------------- *
+*  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  | *
+*  --------------------------------------------------------------------------------- *
+*  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   | *
+*  --------------------------------------------------------------------------------- *
+*  --------------------------------------------------------------------------------- *
+*  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   | *
+*  --------------------------------------------------------------------------------- *
+*  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  | *
+*  --------------------------------------------------------------------------------- *
+*  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR| *
+*  --------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"ontop_i386_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+
+/* mark as using no unregistered SEH handlers */
+.globl	@feat.00
+.def	@feat.00;	.scl	3;	.type	0;	.endef
+.set    @feat.00,   1
+
+.globl	_ontop_fcontext
+.def	_ontop_fcontext;	.scl	2;	.type	32;	.endef
+_ontop_fcontext:
+    /* prepare stack */
+    leal  -0x2c(%esp), %esp
+
+#if !defined(BOOST_USE_TSX)
+    /* save MMX control- and status-word */
+    stmxcsr  (%esp)
+    /* save x87 control-word */
+    fnstcw  0x4(%esp)
+#endif
+
+    /* load NT_TIB */
+    movl  %fs:(0x18), %edx
+    /* load fiber local storage */
+    movl  0x10(%edx), %eax
+    movl  %eax, 0x8(%esp)
+    /* load current dealloction stack */
+    movl  0xe0c(%edx), %eax
+    movl  %eax, 0xc(%esp)
+    /* load current stack limit */
+    movl  0x8(%edx), %eax
+    movl  %eax, 0x10(%esp)
+    /* load current stack base */
+    movl  0x4(%edx), %eax
+    movl  %eax, 0x14(%esp)
+    /* load current SEH exception list */
+    movl  (%edx), %eax
+    movl  %eax, 0x18(%esp)
+
+    movl  %edi, 0x1c(%esp)  /* save EDI */
+    movl  %esi, 0x20(%esp)  /* save ESI */
+    movl  %ebx, 0x24(%esp)  /* save EBX */
+    movl  %ebp, 0x28(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in ECX */
+    movl  %esp, %ecx
+
+    /* first arg of ontop_fcontext() == fcontext to jump to */
+    movl  0x30(%esp), %eax
+
+	/* pass parent fcontext_t */
+	movl  %ecx, 0x30(%eax)
+
+    /* second arg of ontop_fcontext() == data to be transferred */
+    movl  0x34(%esp), %ecx
+
+	/* pass data */
+	movl  %ecx, 0x34(%eax)
+
+    /* third arg of ontop_fcontext() == ontop-function */
+    movl  0x38(%esp), %ecx
+
+    /* restore ESP (pointing to context-data) from EDX */
+    movl  %eax, %esp
+
+#if !defined(BOOST_USE_TSX)
+    /* restore MMX control- and status-word */
+    ldmxcsr  (%esp)
+    /* restore x87 control-word */
+    fldcw  0x4(%esp)
+#endif
+
+    /* restore NT_TIB into EDX */
+    movl  %fs:(0x18), %edx
+    /* restore fiber local storage */
+    movl  0x8(%esp), %eax
+    movl  %eax, 0x10(%edx)
+    /* restore current deallocation stack */
+    movl  0xc(%esp), %eax
+    movl  %eax, 0xe0c(%edx)
+    /* restore current stack limit */
+    movl  0x10(%esp), %eax
+    movl  %eax, 0x08(%edx)
+    /* restore current stack base */
+    movl  0x14(%esp), %eax
+    movl  %eax, 0x04(%edx)
+    /* restore current SEH exception list */
+    movl  0x18(%esp), %eax
+    movl  %eax, (%edx)
+
+    movl  0x1c(%esp), %edi  /* restore EDI */
+    movl  0x20(%esp), %esi  /* restore ESI */
+    movl  0x24(%esp), %ebx  /* restore EBX */
+    movl  0x28(%esp), %ebp  /* restore EBP */
+
+    /* prepare stack */
+    leal  0x2c(%esp), %esp
+
+    /* keep return-address on stack */
+
+    /* jump to context */
+    jmp  *%ecx
+
+.section .drectve
+.ascii " -export:\"_ontop_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_masm.asm
new file mode 100644
index 0000000..82246a4
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_i386_ms_pe_masm.asm
@@ -0,0 +1,124 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ---------------------------------------------------------------------------------
+;  |    0    |    1    |    2    |    3    |    4    |    5    |    6    |    7    |
+;  ---------------------------------------------------------------------------------
+;  |    0h   |   04h   |   08h   |   0ch   |   010h  |   014h  |   018h  |   01ch  |
+;  ---------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw| fc_strg |fc_deallo|  limit  |   base  |  fc_seh |   EDI   |
+;  ---------------------------------------------------------------------------------
+;  ---------------------------------------------------------------------------------
+;  |    8    |    9    |   10    |    11   |    12   |    13   |    14   |    15   |
+;  ---------------------------------------------------------------------------------
+;  |   020h  |  024h   |  028h   |   02ch  |   030h  |   034h  |   038h  |   03ch  |
+;  ---------------------------------------------------------------------------------
+;  |   ESI   |   EBX   |   EBP   |   EIP   |    to   |   data  |  EH NXT |SEH HNDLR|
+;  ---------------------------------------------------------------------------------
+
+.386
+.XMM
+.model flat, c
+.code
+
+ontop_fcontext PROC BOOST_CONTEXT_EXPORT
+    ; prepare stack
+    lea  esp, [esp-02ch]
+
+IFNDEF BOOST_USE_TSX
+    ; save MMX control- and status-word
+    stmxcsr  [esp]
+    ; save x87 control-word
+    fnstcw  [esp+04h]
+ENDIF
+
+    assume  fs:nothing
+    ; load NT_TIB into ECX
+    mov  edx, fs:[018h]
+    assume  fs:error
+    ; load fiber local storage
+    mov  eax, [edx+010h]
+    mov  [esp+08h], eax
+    ; load current deallocation stack
+    mov  eax, [edx+0e0ch]
+    mov  [esp+0ch], eax
+    ; load current stack limit
+    mov  eax, [edx+08h]
+    mov  [esp+010h], eax
+    ; load current stack base
+    mov  eax, [edx+04h]
+    mov  [esp+014h], eax
+    ; load current SEH exception list
+    mov  eax, [edx]
+    mov  [esp+018h], eax
+
+    mov  [esp+01ch], edi  ; save EDI 
+    mov  [esp+020h], esi  ; save ESI 
+    mov  [esp+024h], ebx  ; save EBX 
+    mov  [esp+028h], ebp  ; save EBP 
+
+    ; store ESP (pointing to context-data) in ECX
+    mov  ecx, esp
+
+    ; first arg of ontop_fcontext() == fcontext to jump to
+    mov  eax, [esp+030h]
+
+	; pass parent fcontext_t
+	mov  [eax+030h], ecx
+
+    ; second arg of ontop_fcontext() == data to be transferred
+    mov  ecx, [esp+034h]
+
+	; pass data
+	mov  [eax+034h], ecx
+
+    ; third arg of ontop_fcontext() == ontop-function
+    mov  ecx, [esp+038h]
+    
+    ; restore ESP (pointing to context-data) from EAX
+    mov  esp, eax
+
+IFNDEF BOOST_USE_TSX
+    ; restore MMX control- and status-word
+    ldmxcsr  [esp]
+    ; restore x87 control-word
+    fldcw  [esp+04h]
+ENDIF
+
+    assume  fs:nothing
+    ; load NT_TIB into EDX
+    mov  edx, fs:[018h]
+    assume  fs:error
+    ; restore fiber local storage
+    mov  eax, [esp+08h]
+    mov  [edx+010h], eax
+    ; restore current deallocation stack
+    mov  eax, [esp+0ch]
+    mov  [edx+0e0ch], eax
+    ; restore current stack limit
+    mov  eax, [esp+010h]
+    mov  [edx+08h], eax
+    ; restore current stack base
+    mov  eax, [esp+014h]
+    mov  [edx+04h], eax
+    ; restore current SEH exception list
+    mov  eax, [esp+018h]
+    mov  [edx], eax
+
+    mov  edi, [esp+01ch]  ; restore EDI 
+    mov  esi, [esp+020h]  ; restore ESI 
+    mov  ebx, [esp+024h]  ; restore EBX 
+    mov  ebp, [esp+028h]  ; restore EBP 
+
+    ; prepare stack
+    lea  esp, [esp+02ch]
+
+    ; keep return-address on stack
+
+    ; jump to context
+    jmp ecx
+ontop_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/ontop_i386_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_i386_sysv_elf_gas.S
new file mode 100644
index 0000000..40fe6c2
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_i386_sysv_elf_gas.S
@@ -0,0 +1,90 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |  hidden |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    to   |   data  |                                                            |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "ontop_i386_sysv_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 2
+.type ontop_fcontext,@function
+ontop_fcontext:
+    leal  -0x18(%esp), %esp  /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%esp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%esp)  /* save x87 control-word */
+#endif
+
+    movl  %edi, 0x8(%esp)  /* save EDI */
+    movl  %esi, 0xc(%esp)  /* save ESI */
+    movl  %ebx, 0x10(%esp)  /* save EBX */
+    movl  %ebp, 0x14(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in ECX */
+    movl  %esp, %ecx
+
+    /* first arg of ontop_fcontext() == fcontext to jump to */
+    movl  0x20(%esp), %eax
+
+    /* pass parent fcontext_t */
+    movl  %ecx, 0x20(%eax)
+
+    /* second arg of ontop_fcontext() == data to be transferred */
+    movl  0x24(%esp), %ecx
+
+    /* pass data */
+    movl %ecx, 0x24(%eax)
+
+    /* third arg of ontop_fcontext() == ontop-function */
+    movl  0x28(%esp), %ecx
+
+    /* restore ESP (pointing to context-data) from EAX */
+    movl  %eax, %esp
+
+    /* address of returned transport_t */
+    movl 0x1c(%esp), %eax
+    /* return parent fcontext_t */
+    movl  %ecx, (%eax)
+    /* return data */
+    movl %edx, 0x4(%eax)
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%esp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%esp)  /* restore x87 control-word */
+#endif
+
+    movl  0x8(%esp), %edi  /* restore EDI */
+    movl  0xc(%esp), %esi  /* restore ESI */
+    movl  0x10(%esp), %ebx  /* restore EBX */
+    movl  0x14(%esp), %ebp  /* restore EBP */
+
+    leal  0x18(%esp), %esp  /* prepare stack */
+
+    /* jump to context */
+    jmp *%ecx
+.size ontop_fcontext,.-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_i386_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_i386_sysv_macho_gas.S
new file mode 100644
index 0000000..3a88372
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_i386_sysv_macho_gas.S
@@ -0,0 +1,81 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|   EDI   |   ESI   |   EBX    |   EBP   |   EIP   |    to   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |    10   |    11   |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   data  |                                                                      |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _ontop_fcontext
+.align 2
+_ontop_fcontext:
+    leal  -0x18(%esp), %esp  /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%esp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%esp)  /* save x87 control-word */
+#endif
+
+    movl  %edi, 0x8(%esp)  /* save EDI */
+    movl  %esi, 0xc(%esp)  /* save ESI */
+    movl  %ebx, 0x10(%esp)  /* save EBX */
+    movl  %ebp, 0x14(%esp)  /* save EBP */
+
+    /* store ESP (pointing to context-data) in ECX */
+    movl  %esp, %ecx
+
+    /* first arg of ontop_fcontext() == fcontext to jump to */
+    movl  0x1c(%esp), %eax
+
+    /* pass parent fcontext_t */
+    movl  %ecx, 0x1c(%eax)
+
+    /* second arg of ontop_fcontext() == data to be transferred */
+    movl  0x20(%esp), %ecx
+
+    /* pass data */
+    movl %ecx, 0x20(%eax)
+
+    /* third arg of ontop_fcontext() == ontop-function */
+    movl  0x24(%esp), %ecx
+
+    /* restore ESP (pointing to context-data) from EAX */
+    movl  %eax, %esp
+
+    /* return parent fcontext_t */
+    movl  %ecx, %eax
+    /* returned data is stored in EDX */
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%esp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%esp)  /* restore x87 control-word */
+#endif
+
+    movl  0x8(%esp), %edi  /* restore EDI */
+    movl  0xc(%esp), %esi  /* restore ESI */
+    movl  0x10(%esp), %ebx  /* restore EBX */
+    movl  0x14(%esp), %ebp  /* restore EBP */
+
+    leal  0x18(%esp), %esp  /* prepare stack */
+
+    /* jump to context */
+    jmp *%ecx
diff --git a/lib/context_switcher/asm/fcontext/ontop_i386_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_i386_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..393c5fe
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_i386_x86_64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__i386__)
+    #include "ontop_i386_sysv_macho_gas.S"
+#elif defined(__x86_64__)
+    #include "ontop_x86_64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/ontop_mips32_o32_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_mips32_o32_elf_gas.S
new file mode 100644
index 0000000..c69203c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_mips32_o32_elf_gas.S
@@ -0,0 +1,120 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F20    |    F22    |    F24    |    F26    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F30    |  S0 |  S1 |  S2 |  S3 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |  S4 |  S5 |  S6 |  S7 |  FP |hiddn|  RA |  PC |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |       ABI ARGS        |  GP | FCTX| DATA|     |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "ontop_mips32_o32_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 2
+.type ontop_fcontext,@function
+.ent ontop_fcontext
+ontop_fcontext:
+    # reserve space on stack
+    addiu $sp, $sp, -96
+
+    sw  $s0, 48($sp)  # save S0
+    sw  $s1, 52($sp)  # save S1
+    sw  $s2, 56($sp)  # save S2
+    sw  $s3, 60($sp)  # save S3
+    sw  $s4, 64($sp)  # save S4
+    sw  $s5, 68($sp)  # save S5
+    sw  $s6, 72($sp)  # save S6
+    sw  $s7, 76($sp)  # save S7
+    sw  $fp, 80($sp)  # save FP
+    sw  $a0, 84($sp)  # save hidden, address of returned transfer_t
+    sw  $ra, 88($sp)  # save RA
+    sw  $ra, 92($sp)  # save RA as PC
+
+#if defined(__mips_hard_float)
+    s.d  $f20, ($sp)  # save F20
+    s.d  $f22, 8($sp)  # save F22
+    s.d  $f24, 16($sp)  # save F24
+    s.d  $f26, 24($sp)  # save F26
+    s.d  $f28, 32($sp)  # save F28
+    s.d  $f30, 40($sp)  # save F30
+#endif
+
+    # store SP (pointing to context-data) in A0
+    move  $a0, $sp
+
+    # restore SP (pointing to context-data) from A1
+    move  $sp, $a1
+
+#if defined(__mips_hard_float)
+    l.d  $f20, ($sp)  # restore F20
+    l.d  $f22, 8($sp)  # restore F22
+    l.d  $f24, 16($sp)  # restore F24
+    l.d  $f26, 24($sp)  # restore F26
+    l.d  $f28, 32($sp)  # restore F28
+    l.d  $f30, 40($sp)  # restore F30
+#endif
+
+    lw  $s0, 48($sp)  # restore S0
+    lw  $s1, 52($sp)  # restore S1
+    lw  $s2, 56($sp)  # restore S2
+    lw  $s3, 60($sp)  # restore S3
+    lw  $s4, 64($sp)  # restore S4
+    lw  $s5, 68($sp)  # restore S5
+    lw  $s6, 72($sp)  # restore S6
+    lw  $s7, 76($sp)  # restore S7
+    lw  $fp, 80($sp)  # restore FP
+    lw  $v0, 84($sp)  # restore hidden, address of returned transfer_t
+    lw  $ra, 88($sp)  # restore RA
+
+    # load PC
+    move $t9, $a3
+
+    # adjust stack
+    addiu $sp, $sp, 96
+    
+    # return transfer_t from jump
+    sw  $a0, ($v0)  # fctx of transfer_t
+    sw  $a2, 4($v0) # data of transfer_t
+    # pass transfer_t as first arg in context function
+    # A0 == hidden, A1 == fctx, A2 == data
+    move  $a1, $a0 
+    move  $a0, $v0
+
+    # jump to context
+    jr  $t9
+.end ontop_fcontext
+.size ontop_fcontext, .-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_mips64_n64_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_mips64_n64_elf_gas.S
new file mode 100644
index 0000000..a8a4f8a
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_mips64_n64_elf_gas.S
@@ -0,0 +1,120 @@
+/*
+            Copyright Jiaxun Yang 2018.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |     0     |     8     |    16     |     24    |  *
+ *  -------------------------------------------------  *
+ *  |    F24    |    F25    |    F26    |    F27    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |     32    |    40     |     48    |     56    |  *
+ *  -------------------------------------------------  *
+ *  |    F28    |    F29    |    F30    |    F31    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |     64    |    72     |     80    |     88    |  *
+ *  -------------------------------------------------  *
+ *  |    S0     |    S1     |     S2    |     S3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    S4     |    S5     |     S6    |     S7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    FP     |    GP     |     RA    |     PC    |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ * *****************************************************/
+
+.file "ontop_mips64_n64_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 3
+.type ontop_fcontext,@function
+.ent ontop_fcontext
+ontop_fcontext:
+    # reserve space on stack
+    daddiu $sp, $sp, -160
+
+    sd  $s0, 64($sp)  # save S0
+    sd  $s1, 72($sp)  # save S1
+    sd  $s2, 80($sp)  # save S2
+    sd  $s3, 88($sp)  # save S3
+    sd  $s4, 96($sp)  # save S4
+    sd  $s5, 104($sp) # save S5
+    sd  $s6, 112($sp) # save S6
+    sd  $s7, 120($sp) # save S7
+    sd  $fp, 128($sp) # save FP
+    sd  $ra, 144($sp) # save RA
+    sd  $ra, 152($sp) # save RA as PC
+
+
+    s.d  $f24, 0($sp)   # save F24
+    s.d  $f25, 8($sp)   # save F25
+    s.d  $f26, 16($sp)  # save F26
+    s.d  $f27, 24($sp)  # save F27
+    s.d  $f28, 32($sp)  # save F28
+    s.d  $f29, 40($sp)  # save F29
+    s.d  $f30, 48($sp)  # save F30
+    s.d  $f31, 56($sp)  # save F31
+
+    # store SP (pointing to context-data) in t0
+    move  $t0, $sp
+
+    # restore SP (pointing to context-data) from a0
+    move  $sp, $a0
+
+    l.d  $f24, 0($sp)   # restore F24
+    l.d  $f25, 8($sp)   # restore F25
+    l.d  $f26, 16($sp)  # restore F26
+    l.d  $f27, 24($sp)  # restore F27
+    l.d  $f28, 32($sp)  # restore F28
+    l.d  $f29, 40($sp)  # restore F29
+    l.d  $f30, 48($sp)  # restore F30
+    l.d  $f31, 56($sp)  # restore F31
+
+    ld  $s0, 64($sp)  # restore S0
+    ld  $s1, 72($sp)  # restore S1
+    ld  $s2, 80($sp)  # restore S2
+    ld  $s3, 88($sp)  # restore S3
+    ld  $s4, 96($sp)  # restore S4
+    ld  $s5, 104($sp) # restore S5
+    ld  $s6, 112($sp) # restore S6
+    ld  $s7, 120($sp) # restore S7
+    ld  $fp, 128($sp) # restore FP
+    ld  $ra, 144($sp) # restore RA
+
+    # load PC
+    move $t9, $a2
+
+    # adjust stack
+    daddiu $sp, $sp, 160
+
+    move  $a0, $t0 # move param from t0 to a0 as param
+
+    # jump to context
+    jr  $t9
+.end ontop_fcontext
+.size ontop_fcontext, .-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc32_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc32_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..4632f4c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc32_ppc64_sysv_macho_gas.S
@@ -0,0 +1,16 @@
+/*
+            Copyright Sergue E. Leontiev 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+// Stub file for universal binary
+
+#if defined(__ppc__)
+    #include "ontop_ppc32_sysv_macho_gas.S"
+#elif defined(__ppc64__)
+    #include "ontop_ppc64_sysv_macho_gas.S"
+#else
+    #error "No arch's"
+#endif
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_elf_gas.S
new file mode 100644
index 0000000..464d99d
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_elf_gas.S
@@ -0,0 +1,193 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |bchai|hiddn|   fpscr   |  PC |  CR | R14 | R15 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  | R16 | R17 | R18 | R19 | R20 | R21 | R22 | R23 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  | R24 | R25 | R26 | R27 | R28 | R29 | R30 | R31 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  ------------------------|------------              *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 |              *
+ *  ------------------------|------------              *
+ *  |    F30    |    F31    |bchai|  LR |              *
+ *  ------------------------|------------              *
+ *                                                     *
+ *******************************************************/
+
+.file "ontop_ppc32_sysv_elf_gas.S"
+.text
+.globl ontop_fcontext
+.align 2
+.type ontop_fcontext,@function
+ontop_fcontext:
+    # Linux: ontop_fcontext( hidden transfer_t * R3, R4, R5, R6)
+    # Other: transfer_t R3:R4 = jump_fcontext( R3, R4, R5)
+
+    mflr  %r0  # return address from LR
+    mffs  %f0  # FPSCR
+    mfcr  %r8  # condition register
+
+    stwu  %r1, -240(%r1)  # allocate stack space, R1 % 16 == 0
+    stw   %r0, 244(%r1)   # save LR in caller's frame
+
+#ifdef __linux__
+    stw   %r3, 4(%r1)   # hidden pointer
+#endif
+
+    stfd  %f0, 8(%r1)   # FPSCR
+    stw   %r0, 16(%r1)  # LR as PC
+    stw   %r8, 20(%r1)  # CR
+
+    # Save registers R14 to R31.
+    # Don't change R2, the thread-local storage pointer.
+    # Don't change R13, the small data pointer.
+    stw   %r14, 24(%r1)
+    stw   %r15, 28(%r1)
+    stw   %r16, 32(%r1)
+    stw   %r17, 36(%r1)
+    stw   %r18, 40(%r1)
+    stw   %r19, 44(%r1)
+    stw   %r20, 48(%r1)
+    stw   %r21, 52(%r1)
+    stw   %r22, 56(%r1)
+    stw   %r23, 60(%r1)
+    stw   %r24, 64(%r1)
+    stw   %r25, 68(%r1)
+    stw   %r26, 72(%r1)
+    stw   %r27, 76(%r1)
+    stw   %r28, 80(%r1)
+    stw   %r29, 84(%r1)
+    stw   %r30, 88(%r1)
+    stw   %r31, 92(%r1)
+
+    # Save registers F14 to F31 in slots with 8-byte alignment.
+    # 4-byte alignment may stall the pipeline of some processors.
+    # Less than 4 may cause alignment traps.
+    stfd  %f14, 96(%r1)
+    stfd  %f15, 104(%r1)
+    stfd  %f16, 112(%r1)
+    stfd  %f17, 120(%r1)
+    stfd  %f18, 128(%r1)
+    stfd  %f19, 136(%r1)
+    stfd  %f20, 144(%r1)
+    stfd  %f21, 152(%r1)
+    stfd  %f22, 160(%r1)
+    stfd  %f23, 168(%r1)
+    stfd  %f24, 176(%r1)
+    stfd  %f25, 184(%r1)
+    stfd  %f26, 192(%r1)
+    stfd  %f27, 200(%r1)
+    stfd  %f28, 208(%r1)
+    stfd  %f29, 216(%r1)
+    stfd  %f30, 224(%r1)
+    stfd  %f31, 232(%r1)
+
+    # store RSP (pointing to context-data) in R7/R6
+    # restore RSP (pointing to context-data) from R4/R3
+#ifdef __linux__
+    mr   %r7, %r1
+    mr   %r1, %r4
+    lwz  %r3, 4(%r1)   # hidden pointer
+#else
+    mr   %r6, %r1
+    mr   %r1, %r3
+#endif
+
+    # ignore PC at 16(%r1)
+    lfd  %f0, 8(%r1)   # FPSCR
+    lwz  %r8, 20(%r1)  # CR
+
+    mtfsf  0xff, %f0   # restore FPSCR
+    mtcr   %r8         # restore CR
+
+    # restore R14 to R31
+    lwz  %r14, 24(%r1)
+    lwz  %r15, 28(%r1)
+    lwz  %r16, 32(%r1)
+    lwz  %r17, 36(%r1)
+    lwz  %r18, 40(%r1)
+    lwz  %r19, 44(%r1)
+    lwz  %r20, 48(%r1)
+    lwz  %r21, 52(%r1)
+    lwz  %r22, 56(%r1)
+    lwz  %r23, 60(%r1)
+    lwz  %r24, 64(%r1)
+    lwz  %r25, 68(%r1)
+    lwz  %r26, 72(%r1)
+    lwz  %r27, 76(%r1)
+    lwz  %r28, 80(%r1)
+    lwz  %r29, 84(%r1)
+    lwz  %r30, 88(%r1)
+    lwz  %r31, 92(%r1)
+
+    # restore F14 to F31
+    lfd  %f14, 96(%r1)
+    lfd  %f15, 104(%r1)
+    lfd  %f16, 112(%r1)
+    lfd  %f17, 120(%r1)
+    lfd  %f18, 128(%r1)
+    lfd  %f19, 136(%r1)
+    lfd  %f20, 144(%r1)
+    lfd  %f21, 152(%r1)
+    lfd  %f22, 160(%r1)
+    lfd  %f23, 168(%r1)
+    lfd  %f24, 176(%r1)
+    lfd  %f25, 184(%r1)
+    lfd  %f26, 192(%r1)
+    lfd  %f27, 200(%r1)
+    lfd  %f28, 208(%r1)
+    lfd  %f29, 216(%r1)
+    lfd  %f30, 224(%r1)
+    lfd  %f31, 232(%r1)
+
+    # restore LR from caller's frame
+    lwz   %r0, 244(%r1)
+    mtlr  %r0
+
+    # adjust stack
+    addi  %r1, %r1, 240
+
+    # see tail_ppc32_sysv_elf_gas.cpp
+    # Linux: fcontext_ontop_tail( hidden transfer_t * R3, R4, R5, R6, R7)
+    # Other: transfer_t R3:R4 = fcontext_ontop_tail( R3, R4, R5, R6)
+    b ontop_fcontext_tail
+.size ontop_fcontext, .-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_macho_gas.S
new file mode 100644
index 0000000..1eb5f93
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_macho_gas.S
@@ -0,0 +1,201 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.globl _ontop_fcontext
+.align 2
+_ontop_fcontext:
+    # reserve space on stack
+    subi  r1, r1, 244
+
+    stfd  f14, 0(r1)  # save F14
+    stfd  f15, 8(r1)  # save F15
+    stfd  f16, 16(r1)  # save F16
+    stfd  f17, 24(r1)  # save F17
+    stfd  f18, 32(r1)  # save F18
+    stfd  f19, 40(r1)  # save F19
+    stfd  f20, 48(r1)  # save F20
+    stfd  f21, 56(r1)  # save F21
+    stfd  f22, 64(r1)  # save F22
+    stfd  f23, 72(r1)  # save F23
+    stfd  f24, 80(r1)  # save F24
+    stfd  f25, 88(r1)  # save F25
+    stfd  f26, 96(r1)  # save F26
+    stfd  f27, 104(r1)  # save F27
+    stfd  f28, 112(r1)  # save F28
+    stfd  f29, 120(r1)  # save F29
+    stfd  f30, 128(r1)  # save F30
+    stfd  f31, 136(r1)  # save F31
+    mffs  f0  # load FPSCR
+    stfd  f0, 144(r1)  # save FPSCR
+
+    stw  r13, 152(r1)  # save R13
+    stw  r14, 156(r1)  # save R14
+    stw  r15, 160(r1)  # save R15
+    stw  r16, 164(r1)  # save R16
+    stw  r17, 168(r1)  # save R17
+    stw  r18, 172(r1)  # save R18
+    stw  r19, 176(r1)  # save R19
+    stw  r20, 180(r1)  # save R20
+    stw  r21, 184(r1)  # save R21
+    stw  r22, 188(r1)  # save R22
+    stw  r23, 192(r1)  # save R23
+    stw  r24, 196(r1)  # save R24
+    stw  r25, 200(r1)  # save R25
+    stw  r26, 204(r1)  # save R26
+    stw  r27, 208(r1)  # save R27
+    stw  r28, 212(r1)  # save R28
+    stw  r29, 216(r1)  # save R29
+    stw  r30, 220(r1)  # save R30
+    stw  r31, 224(r1)  # save R31
+    stw  r3,  228(r1)  # save hidden
+
+    # save CR
+    mfcr  r0
+    stw   r0, 232(r1)
+    # save LR
+    mflr  r0
+    stw   r0, 236(r1)
+    # save LR as PC
+    stw   r0, 240(r1)
+
+    # store RSP (pointing to context-data) in R7
+    mr  r7, r1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    lfd  f14, 0(r1)  # restore F14
+    lfd  f15, 8(r1)  # restore F15
+    lfd  f16, 16(r1)  # restore F16
+    lfd  f17, 24(r1)  # restore F17
+    lfd  f18, 32(r1)  # restore F18
+    lfd  f19, 40(r1)  # restore F19
+    lfd  f20, 48(r1)  # restore F20
+    lfd  f21, 56(r1)  # restore F21
+    lfd  f22, 64(r1)  # restore F22
+    lfd  f23, 72(r1)  # restore F23
+    lfd  f24, 80(r1)  # restore F24
+    lfd  f25, 88(r1)  # restore F25
+    lfd  f26, 96(r1)  # restore F26
+    lfd  f27, 104(r1)  # restore F27
+    lfd  f28, 112(r1)  # restore F28
+    lfd  f29, 120(r1)  # restore F29
+    lfd  f30, 128(r1)  # restore F30
+    lfd  f31, 136(r1)  # restore F31
+    lfd  f0,  144(r1)  # load FPSCR
+    mtfsf  0xff, f0  # restore FPSCR
+
+    lwz  r13, 152(r1)  # restore R13
+    lwz  r14, 156(r1)  # restore R14
+    lwz  r15, 160(r1)  # restore R15
+    lwz  r16, 164(r1)  # restore R16
+    lwz  r17, 168(r1)  # restore R17
+    lwz  r18, 172(r1)  # restore R18
+    lwz  r19, 176(r1)  # restore R19
+    lwz  r20, 180(r1)  # restore R20
+    lwz  r21, 184(r1)  # restore R21
+    lwz  r22, 188(r1)  # restore R22
+    lwz  r23, 192(r1)  # restore R23
+    lwz  r24, 196(r1)  # restore R24
+    lwz  r25, 200(r1)  # restore R25
+    lwz  r26, 204(r1)  # restore R26
+    lwz  r27, 208(r1)  # restore R27
+    lwz  r28, 212(r1)  # restore R28
+    lwz  r29, 216(r1)  # restore R29
+    lwz  r30, 220(r1)  # restore R30
+    lwz  r31, 224(r1)  # restore R31
+    lwz  r4,  228(r1)  # restore hidden
+
+    # restore CR
+    lwz   r0, 232(r1)
+    mtcr  r0
+    # restore LR
+    lwz   r0, 236(r1)
+    mtlr  r0
+    # ignore PC
+
+    # adjust stack
+    addi  r1, r1, 244
+
+    # return transfer_t 
+    stw  r7, 0(r4)
+    stw  r5, 4(r4)
+
+    # restore CTR
+    mtctr r6
+
+    # jump to ontop-function
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_xcoff_gas.S
new file mode 100644
index 0000000..a3c9fa2
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc32_sysv_xcoff_gas.S
@@ -0,0 +1,203 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    F14    |    F15    |    F16    |    F17    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    F18    |    F19    |    F20    |    F21    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    F22    |    F23    |    F24    |    F25    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    F26    |    F27    |    F28    |    F29    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    F30    |    F31    |   fpscr   | R13 | R14 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | R31 |hiddn|  CR |  LR |  PC |bchai|linkr| FCTX|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  64 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | 256 |                                         |  *
+ *  -------------------------------------------------  *
+ *  | DATA|                                         |  * 
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+.globl .ontop_fcontext
+.globl  ontop_fcontext[DS]
+.align 2 
+.csect	ontop_fcontext[DS]
+ontop_fcontext:
+  .long	.ontop_fcontext
+.ontop_fcontext:
+    # reserve space on stack
+    subi  r1, r1, 244
+
+    stfd  f14, 0(r1)  # save F14
+    stfd  f15, 8(r1)  # save F15
+    stfd  f16, 16(r1)  # save F16
+    stfd  f17, 24(r1)  # save F17
+    stfd  f18, 32(r1)  # save F18
+    stfd  f19, 40(r1)  # save F19
+    stfd  f20, 48(r1)  # save F20
+    stfd  f21, 56(r1)  # save F21
+    stfd  f22, 64(r1)  # save F22
+    stfd  f23, 72(r1)  # save F23
+    stfd  f24, 80(r1)  # save F24
+    stfd  f25, 88(r1)  # save F25
+    stfd  f26, 96(r1)  # save F26
+    stfd  f27, 104(r1)  # save F27
+    stfd  f28, 112(r1)  # save F28
+    stfd  f29, 120(r1)  # save F29
+    stfd  f30, 128(r1)  # save F30
+    stfd  f31, 136(r1)  # save F31
+    mffs  f0  # load FPSCR
+    stfd  f0, 144(r1)  # save FPSCR
+
+    stw  r13, 152(r1)  # save R13
+    stw  r14, 156(r1)  # save R14
+    stw  r15, 160(r1)  # save R15
+    stw  r16, 164(r1)  # save R16
+    stw  r17, 168(r1)  # save R17
+    stw  r18, 172(r1)  # save R18
+    stw  r19, 176(r1)  # save R19
+    stw  r20, 180(r1)  # save R20
+    stw  r21, 184(r1)  # save R21
+    stw  r22, 188(r1)  # save R22
+    stw  r23, 192(r1)  # save R23
+    stw  r24, 196(r1)  # save R24
+    stw  r25, 200(r1)  # save R25
+    stw  r26, 204(r1)  # save R26
+    stw  r27, 208(r1)  # save R27
+    stw  r28, 212(r1)  # save R28
+    stw  r29, 216(r1)  # save R29
+    stw  r30, 220(r1)  # save R30
+    stw  r31, 224(r1)  # save R31
+    stw  r3,  228(r1)  # save hidden
+
+    # save CR
+    mfcr  r0
+    stw   r0, 232(r1)
+    # save LR
+    mflr  r0
+    stw   r0, 236(r1)
+    # save LR as PC
+    stw   r0, 240(r1)
+
+    # store RSP (pointing to context-data) in R7
+    mr  r7, r1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    lfd  f14, 0(r1)  # restore F14
+    lfd  f15, 8(r1)  # restore F15
+    lfd  f16, 16(r1)  # restore F16
+    lfd  f17, 24(r1)  # restore F17
+    lfd  f18, 32(r1)  # restore F18
+    lfd  f19, 40(r1)  # restore F19
+    lfd  f20, 48(r1)  # restore F20
+    lfd  f21, 56(r1)  # restore F21
+    lfd  f22, 64(r1)  # restore F22
+    lfd  f23, 72(r1)  # restore F23
+    lfd  f24, 80(r1)  # restore F24
+    lfd  f25, 88(r1)  # restore F25
+    lfd  f26, 96(r1)  # restore F26
+    lfd  f27, 104(r1)  # restore F27
+    lfd  f28, 112(r1)  # restore F28
+    lfd  f29, 120(r1)  # restore F29
+    lfd  f30, 128(r1)  # restore F30
+    lfd  f31, 136(r1)  # restore F31
+    lfd  f0,  144(r1)  # load FPSCR
+    mtfsf  0xff, f0  # restore FPSCR
+
+    lwz  r13, 152(r1)  # restore R13
+    lwz  r14, 156(r1)  # restore R14
+    lwz  r15, 160(r1)  # restore R15
+    lwz  r16, 164(r1)  # restore R16
+    lwz  r17, 168(r1)  # restore R17
+    lwz  r18, 172(r1)  # restore R18
+    lwz  r19, 176(r1)  # restore R19
+    lwz  r20, 180(r1)  # restore R20
+    lwz  r21, 184(r1)  # restore R21
+    lwz  r22, 188(r1)  # restore R22
+    lwz  r23, 192(r1)  # restore R23
+    lwz  r24, 196(r1)  # restore R24
+    lwz  r25, 200(r1)  # restore R25
+    lwz  r26, 204(r1)  # restore R26
+    lwz  r27, 208(r1)  # restore R27
+    lwz  r28, 212(r1)  # restore R28
+    lwz  r29, 216(r1)  # restore R29
+    lwz  r30, 220(r1)  # restore R30
+    lwz  r31, 224(r1)  # restore R31
+    lwz  r4,  228(r1)  # restore hidden
+
+    # restore CR
+    lwz   r0, 232(r1)
+    mtcr  r0
+    # restore LR
+    lwz   r0, 236(r1)
+    mtlr  r0
+    # ignore PC
+
+    # adjust stack
+    addi  r1, r1, 244
+
+    # return transfer_t 
+    stw  r7, 0(r4)
+    stw  r5, 4(r4)
+
+    # restore CTR
+    mtctr r6
+
+    # jump to ontop-function
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_elf_gas.S
new file mode 100644
index 0000000..cd97f45
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_elf_gas.S
@@ -0,0 +1,244 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "ontop_ppc64_sysv_elf_gas.S"
+.globl ontop_fcontext
+#if _CALL_ELF == 2
+	.text
+	.align 2
+ontop_fcontext:
+        addis   %r2, %r12, .TOC.-ontop_fcontext@ha
+        addi    %r2, %r2, .TOC.-ontop_fcontext@l
+        .localentry ontop_fcontext, . - ontop_fcontext
+#else
+	.section ".opd","aw"
+	.align 3
+ontop_fcontext:
+# ifdef _CALL_LINUX
+        .quad   .L.ontop_fcontext,.TOC.@tocbase,0
+        .type   ontop_fcontext,@function
+        .text
+        .align 2
+.L.ontop_fcontext:
+# else
+        .hidden .ontop_fcontext
+        .globl  .ontop_fcontext
+        .quad   .ontop_fcontext,.TOC.@tocbase,0
+        .size   ontop_fcontext,24
+        .type   .ontop_fcontext,@function
+        .text
+        .align 2
+.ontop_fcontext:
+# endif
+#endif
+    # reserve space on stack
+    subi  %r1, %r1, 184
+
+#if _CALL_ELF != 2
+    std  %r2,  0(%r1)  # save TOC
+#endif
+    std  %r14, 8(%r1)  # save R14
+    std  %r15, 16(%r1)  # save R15
+    std  %r16, 24(%r1)  # save R16
+    std  %r17, 32(%r1)  # save R17
+    std  %r18, 40(%r1)  # save R18
+    std  %r19, 48(%r1)  # save R19
+    std  %r20, 56(%r1)  # save R20
+    std  %r21, 64(%r1)  # save R21
+    std  %r22, 72(%r1)  # save R22
+    std  %r23, 80(%r1)  # save R23
+    std  %r24, 88(%r1)  # save R24
+    std  %r25, 96(%r1)  # save R25
+    std  %r26, 104(%r1)  # save R26
+    std  %r27, 112(%r1)  # save R27
+    std  %r28, 120(%r1)  # save R28
+    std  %r29, 128(%r1)  # save R29
+    std  %r30, 136(%r1)  # save R30
+    std  %r31, 144(%r1)  # save R31
+#if _CALL_ELF != 2
+    std  %r3,  152(%r1)  # save hidden
+#endif
+
+    # save CR
+    mfcr  %r0
+    std   %r0, 160(%r1)
+    # save LR
+    mflr  %r0
+    std   %r0, 168(%r1)
+    # save LR as PC
+    std   %r0, 176(%r1)
+
+    # store RSP (pointing to context-data) in R7
+    mr  %r7, %r1
+
+#if _CALL_ELF == 2
+    # restore RSP (pointing to context-data) from R3
+    mr  %r1, %r3
+#else
+    # restore RSP (pointing to context-data) from R4
+    mr  %r1, %r4
+#endif
+
+    ld  %r14, 8(%r1)  # restore R14
+    ld  %r15, 16(%r1)  # restore R15
+    ld  %r16, 24(%r1)  # restore R16
+    ld  %r17, 32(%r1)  # restore R17
+    ld  %r18, 40(%r1)  # restore R18
+    ld  %r19, 48(%r1)  # restore R19
+    ld  %r20, 56(%r1)  # restore R20
+    ld  %r21, 64(%r1)  # restore R21
+    ld  %r22, 72(%r1)  # restore R22
+    ld  %r23, 80(%r1)  # restore R23
+    ld  %r24, 88(%r1)  # restore R24
+    ld  %r25, 96(%r1)  # restore R25
+    ld  %r26, 104(%r1)  # restore R26
+    ld  %r27, 112(%r1)  # restore R27
+    ld  %r28, 120(%r1)  # restore R28
+    ld  %r29, 128(%r1)  # restore R29
+    ld  %r30, 136(%r1)  # restore R30
+    ld  %r31, 144(%r1)  # restore R31
+#if _CALL_ELF != 2
+    ld  %r3,  152(%r1)  # restore hidden
+#endif
+
+    # restore CR
+    ld  %r0, 160(%r1)
+    mtcr  %r0
+
+#if _CALL_ELF == 2
+    # restore CTR
+    mtctr  %r5
+
+    # store cb entrypoint in %r12, used for TOC calculation
+    mr %r12, %r5
+
+    # copy transfer_t into ontop_fn arg registers
+    mr  %r3, %r7
+    # arg pointer already in %r4
+#else
+    # copy transfer_t into ontop_fn arg registers
+    mr  %r4, %r7
+    # arg pointer already in %r5
+    # hidden arg already in %r3
+
+    # restore CTR
+    ld   %r7, 0(%r6)
+    mtctr  %r7
+    # restore TOC
+    ld   %r2, 8(%r6)
+
+    # zero in r3 indicates first jump to context-function
+    cmpdi  %r3, 0
+    beq  use_entry_arg
+#endif
+
+return_to_ctx:
+    # restore LR
+    ld  %r0, 168(%r1)
+    mtlr  %r0
+
+    # adjust stack
+    addi  %r1, %r1, 184
+
+    # jump to context
+    bctr
+
+#if _CALL_ELF == 2
+	.size ontop_fcontext, .-ontop_fcontext
+#else
+use_entry_arg:
+    # compute return-value struct address
+    # (passed has hidden arg to ontop_fn)
+    addi  %r3, %r1, 8
+
+    # jump to context and update LR
+    bctrl
+
+    # restore CTR
+    ld   %r7, 176(%r1)
+    mtctr  %r7
+#if _CALL_ELF != 2
+    # restore TOC
+    ld   %r2, 0(%r1)
+#endif
+
+    # copy returned transfer_t into entry_fn arg registers
+    ld  %r3, 8(%r1)
+    ld  %r4, 16(%r1)
+
+    b  return_to_ctx
+# ifdef _CALL_LINUX
+	.size .ontop_fcontext, .-.L.ontop_fcontext
+# else
+	.size .ontop_fcontext, .-.ontop_fcontext
+# endif
+#endif
+
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_macho_gas.S
new file mode 100644
index 0000000..5de8acd
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_macho_gas.S
@@ -0,0 +1,151 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  |  0  |  4  |  8  |  12 |  16 |  20 |  24 |  28 |  *
+ *  -------------------------------------------------  *
+ *  |    TOC    |    R14    |    R15    |    R16    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  |  32 |  36 |  40 |  44 |  48 |  52 |  56 |  60 |  *
+ *  -------------------------------------------------  *
+ *  |    R17    |    R18    |     R19   |    R20    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  |  64 |  68 |  72 |  76 |  80 |  84 |  88 |  92 |  *
+ *  -------------------------------------------------  *
+ *  |    R21    |    R22    |    R23    |    R24    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  |  96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 |  *
+ *  -------------------------------------------------  *
+ *  |    R25    |    R26    |    R27    |    R28    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 |  *
+ *  -------------------------------------------------  *
+ *  |    R29    |    R30    |    R31    |   hidden  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 |  43 |  44 |  45 |  46 |  47 |  *
+ *  -------------------------------------------------  *
+ *  | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 |  *
+ *  -------------------------------------------------  *
+ *  |     CR    |     LR    |     PC    | back-chain|  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  *
+ *  -------------------------------------------------  *
+ *  | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 |  *
+ *  -------------------------------------------------  *
+ *  |  cr saved |  lr saved |  compiler |   linker  |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  56 |  57 |  58 |  59 |  60 |  61 |  62 |  63 |  *
+ *  -------------------------------------------------  *
+ *  | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 |  *
+ *  -------------------------------------------------  *
+ *  | TOC saved |    FCTX   |    DATA   |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.text
+.align 2
+.globl _ontop_fcontext
+
+_ontop_fcontext:
+    ; reserve space on stack
+    subi  r1, r1, 184
+
+    std  r14, 8(r1)  ; save R14
+    std  r15, 16(r1)  ; save R15
+    std  r16, 24(r1)  ; save R16
+    std  r17, 32(r1)  ; save R17
+    std  r18, 40(r1)  ; save R18
+    std  r19, 48(r1)  ; save R19
+    std  r20, 56(r1)  ; save R20
+    std  r21, 64(r1)  ; save R21
+    std  r22, 72(r1)  ; save R22
+    std  r23, 80(r1)  ; save R23
+    std  r24, 88(r1)  ; save R24
+    std  r25, 96(r1)  ; save R25
+    std  r26, 104(r1)  ; save R26
+    std  r27, 112(r1)  ; save R27
+    std  r28, 120(r1)  ; save R28
+    std  r29, 128(r1)  ; save R29
+    std  r30, 136(r1)  ; save R30
+    std  r31, 144(r1)  ; save R31
+    std  r3,  152(r1)  ; save hidden
+
+    ; save CR
+    mfcr  r0
+    std   r0, 160(r1)
+    ; save LR
+    mflr  r0
+    std   r0, 168(r1)
+    ; save LR as PC
+    std   r0, 176(r1)
+
+    ; store RSP (pointing to context-data) in R7
+    mr  r7, r1
+
+    ; restore RSP (pointing to context-data) from R4
+    mr  r1, r4
+
+    ld  r14, 8(r1)  ; restore R14
+    ld  r15, 16(r1)  ; restore R15
+    ld  r16, 24(r1)  ; restore R16
+    ld  r17, 32(r1)  ; restore R17
+    ld  r18, 40(r1)  ; restore R18
+    ld  r19, 48(r1)  ; restore R19
+    ld  r20, 56(r1)  ; restore R20
+    ld  r21, 64(r1)  ; restore R21
+    ld  r22, 72(r1)  ; restore R22
+    ld  r23, 80(r1)  ; restore R23
+    ld  r24, 88(r1)  ; restore R24
+    ld  r25, 96(r1)  ; restore R25
+    ld  r26, 104(r1)  ; restore R26
+    ld  r27, 112(r1)  ; restore R27
+    ld  r28, 120(r1)  ; restore R28
+    ld  r29, 128(r1)  ; restore R29
+    ld  r30, 136(r1)  ; restore R30
+    ld  r31, 144(r1)  ; restore R31
+    ld  r4,  152(r1)  ; restore hidden
+
+    ; restore CR
+    ld  r0, 160(r1)
+    mtcr  r0
+    ; restore LR
+    ld  r0, 168(r1)
+    mtlr  r0
+    ; ignore PC
+
+    ; adjust stack
+    addi  r1, r1, 184
+
+    ; return transfer_t
+    std  r7, 0(r4)
+    std  r5, 8(r4)
+
+    ; restore CTR
+    mtctr  r6
+
+    ; jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_xcoff_gas.S b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_xcoff_gas.S
new file mode 100644
index 0000000..93f8c23
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_ppc64_sysv_xcoff_gas.S
@@ -0,0 +1,83 @@
+.align 2
+.globl .ontop_fcontext
+.ontop_fcontext:
+    # reserve space on stack
+    subi  1, 1, 184
+
+    std  13, 0(1)  # save R13
+    std  14, 8(1)  # save R14
+    std  15, 16(1)  # save R15
+    std  16, 24(1)  # save R16
+    std  17, 32(1)  # save R17
+    std  18, 40(1)  # save R18
+    std  19, 48(1)  # save R19
+    std  20, 56(1)  # save R20
+    std  21, 64(1)  # save R21
+    std  22, 72(1)  # save R22
+    std  23, 80(1)  # save R23
+    std  24, 88(1)  # save R24
+    std  25, 96(1)  # save R25
+    std  26, 104(1)  # save R26
+    std  27, 112(1)  # save R27
+    std  29, 120(1)  # save R28
+    std  29, 128(1)  # save R29
+    std  30, 136(1)  # save R30
+    std  31, 144(1)  # save R31
+    std  3,  152(1)  # save hidden
+
+    # save CR
+    mfcr  0
+    std  0, 160(1)
+    # save LR
+    mflr  0
+    std  0, 168(1)
+    # save LR as PC
+    std  0, 176(1)
+
+    # store RSP (pointing to context-data) in R7
+    mr  7, 1
+
+    # restore RSP (pointing to context-data) from R4
+    mr  1, 4
+
+    ld  13, 0(1)  # restore R13
+    ld  14, 8(1)  # restore R14
+    ld  15, 16(1)  # restore R15
+    ld  16, 24(1)  # restore R16
+    ld  17, 32(1)  # restore R17
+    ld  18, 40(1)  # restore R18
+    ld  19, 48(1)  # restore R19
+    ld  20, 56(1)  # restore R20
+    ld  21, 64(1)  # restore R21
+    ld  22, 72(1)  # restore R22
+    ld  23, 80(1)  # restore R23
+    ld  24, 88(1)  # restore R24
+    ld  25, 96(1)  # restore R25
+    ld  26, 104(1)  # restore R26
+    ld  27, 112(1)  # restore R27
+    ld  28, 120(1)  # restore R28
+    ld  29, 128(1)  # restore R29
+    ld  30, 136(1)  # restore R30
+    ld  31, 144(1)  # restore R31
+    ld  4,  152(1)  # restore hidden
+
+    # restore CR
+    ld  0, 160(1)
+    mtcr  0
+    # restore LR
+    ld  0, 168(1)
+    mtlr  0
+    # ignore PC
+
+    # adjust stack
+    addi  1, 1, 184
+
+    # return transfer_t
+    std  7, 0(4)
+    std  5, 8(4)
+
+    # restore CTR
+    mtctr  6
+
+    # jump to context
+    bctr
diff --git a/lib/context_switcher/asm/fcontext/ontop_riscv64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_riscv64_sysv_elf_gas.S
new file mode 100644
index 0000000..61ab46b
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_riscv64_sysv_elf_gas.S
@@ -0,0 +1,149 @@
+/*
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt)
+*/
+/*******************************************************
+ *                                                     *
+ *  -------------------------------------------------  *
+ *  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+ *  -------------------------------------------------  *
+ *  | 0x0 | 0x4 | 0x8 | 0xc | 0x10| 0x14| 0x18| 0x1c|  *
+ *  -------------------------------------------------  *
+ *  |    fs0    |    fs1    |    fs2    |    fs3    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+ *  -------------------------------------------------  *
+ *  | 0x20| 0x24| 0x28| 0x2c| 0x30| 0x34| 0x38| 0x3c|  *
+ *  -------------------------------------------------  *
+ *  |    fs4    |    fs5    |    fs6    |    fs7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+ *  -------------------------------------------------  *
+ *  | 0x40| 0x44| 0x48| 0x4c| 0x50| 0x54| 0x58| 0x5c|  *
+ *  -------------------------------------------------  *
+ *  |    fs8    |    fs9    |    fs10   |    fs11   |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  *
+ *  -------------------------------------------------  *
+ *  | 0x60| 0x64| 0x68| 0x6c| 0x70| 0x74| 0x78| 0x7c|  *
+ *  -------------------------------------------------  *
+ *  |    s0     |    s1     |    s2     |    s3     |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  32 |  33 |  34 |  35 |  36 |  37 |  38 |  39 |  *
+ *  -------------------------------------------------  *
+ *  | 0x80| 0x84| 0x88| 0x8c| 0x90| 0x94| 0x98| 0x9c|  *
+ *  -------------------------------------------------  *
+ *  |    s4     |    s5     |    s6     |     s7    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  40 |  41 |  42 | 43  |  44 | 45  |  46 | 47  |  *
+ *  -------------------------------------------------  *
+ *  | 0xa0| 0xa4| 0xa8| 0xac| 0xb0| 0xb4| 0xb8| 0xbc|  *
+ *  -------------------------------------------------  *
+ *  |     s8    |     s9    |    s10    |    s11    |  *
+ *  -------------------------------------------------  *
+ *  -------------------------------------------------  *
+ *  |  48 |  49 |  50 | 51  |     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  | 0xc0| 0xc4| 0xc8| 0xcc|     |     |     |     |  *
+ *  -------------------------------------------------  *
+ *  |     ra    |     pc    |           |           |  *
+ *  -------------------------------------------------  *
+ *                                                     *
+ *******************************************************/
+
+.file "ontop_riscv64_sysv_elf_gas.S"
+.text
+.align  1
+.global ontop_fcontext
+.type   ontop_fcontext, %function
+ontop_fcontext:
+    # prepare stack for GP + FPU
+    addi  sp, sp, -0xd0
+
+    # save fs0 - fs11
+    fsd  fs0, 0x00(sp)
+    fsd  fs1, 0x08(sp)
+    fsd  fs2, 0x10(sp)
+    fsd  fs3, 0x18(sp)
+    fsd  fs4, 0x20(sp)
+    fsd  fs5, 0x28(sp)
+    fsd  fs6, 0x30(sp)
+    fsd  fs7, 0x38(sp)
+    fsd  fs8, 0x40(sp)
+    fsd  fs9, 0x48(sp)
+    fsd  fs10, 0x50(sp)
+    fsd  fs11, 0x58(sp)
+
+    # save s0-s11, ra
+    sd  s0, 0x60(sp)
+    sd  s1, 0x68(sp)
+    sd  s2, 0x70(sp)
+    sd  s3, 0x78(sp)
+    sd  s4, 0x80(sp)
+    sd  s5, 0x88(sp)
+    sd  s6, 0x90(sp)
+    sd  s7, 0x98(sp)
+    sd  s8, 0xa0(sp)
+    sd  s9, 0xa8(sp)
+    sd  s10, 0xb0(sp)
+    sd  s11, 0xb8(sp)
+    sd  ra, 0xc0(sp)
+
+    # save RA as PC
+    sd  ra, 0xc8(sp)
+
+    # store SP (pointing to context-data) in A3
+    mv  a3, sp
+
+    # restore SP (pointing to context-data) from A0
+    mv  sp, a0
+
+    # load fs0 - fs11
+    fld  fs0, 0x00(sp)
+    fld  fs1, 0x08(sp)
+    fld  fs2, 0x10(sp)
+    fld  fs3, 0x18(sp)
+    fld  fs4, 0x20(sp)
+    fld  fs5, 0x28(sp)
+    fld  fs6, 0x30(sp)
+    fld  fs7, 0x38(sp)
+    fld  fs8, 0x40(sp)
+    fld  fs9, 0x48(sp)
+    fld  fs10, 0x50(sp)
+    fld  fs11, 0x58(sp)
+
+    # load s0-s11,ra
+    ld  s0, 0x60(sp)
+    ld  s1, 0x68(sp)
+    ld  s2, 0x70(sp)
+    ld  s3, 0x78(sp)
+    ld  s4, 0x80(sp)
+    ld  s5, 0x88(sp)
+    ld  s6, 0x90(sp)
+    ld  s7, 0x98(sp)
+    ld  s8, 0xa0(sp)
+    ld  s9, 0xa8(sp)
+    ld  s10, 0xb0(sp)
+    ld  s11, 0xb8(sp)
+    ld  ra, 0xc0(sp)
+
+    # return transfer_t from jump
+    # pass transfer_t as first arg in context function
+    # a0 == FCTX, a1 == DATA
+    mv a0, a3
+
+    # skip pc
+    # restore stack from GP + FPU
+    addi  sp, sp, 0xd0
+
+    # jump to ontop-function
+    jr a2
+.size   ontop_fcontext,.-ontop_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_s390x_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_s390x_sysv_elf_gas.S
new file mode 100644
index 0000000..4488654
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_s390x_sysv_elf_gas.S
@@ -0,0 +1,112 @@
+/*******************************************************
+*                                                     *
+*  -------------------------------------------------  *
+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *
+*  -------------------------------------------------  *
+*  |     0     |     8     |    16     |     24    |  *
+*  -------------------------------------------------  *
+*  |    R6     |    R7     |    R8     |    R9     |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *
+*  -------------------------------------------------  *
+*  |     32    |    40     |     48    |     56    |  *
+*  -------------------------------------------------  *
+*  |    R10    |    R11    |     R12   |     R13   |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *
+*  -------------------------------------------------  *
+*  |     64    |    72     |     80    |     88    |  *
+*  -------------------------------------------------  *
+*  |   R14/LR  |    R15    |     F1    |     F3    |  *
+*  -------------------------------------------------  *
+*  -------------------------------------------------  *
+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *
+*  -------------------------------------------------  *
+*  |     96    |    104    |    112    |    120    |  *
+*  -------------------------------------------------  *
+*  |    F5     |    F7     |     PC    |           |  *
+*  -------------------------------------------------  *
+* *****************************************************/
+
+.file  "ontop_s390x_sysv_elf_gas.S"
+.text
+.align  4 # According to the sample code in the ELF ABI docs
+.global ontop_fcontext
+.type   ontop_fcontext, @function
+
+#define GR_OFFSET	0
+#define LR_OFFSET	64
+#define SP_OFFSET	72
+#define FP_OFFSET	80
+#define PC_OFFSET	112
+#define L_CTX		120
+
+ontop_fcontext:
+    
+    # Reserved the space for stack to store the data of current context
+    # before we jump to the new context.
+    aghi %r15,-L_CTX
+
+    # save the registers to the stack
+    stmg %r6, %r15, GR_OFFSET(%r15)
+
+    # save the floating point registers
+    std  %f0,FP_OFFSET(%r15)
+    std  %f3,FP_OFFSET+8(%r15)
+    std  %f5,FP_OFFSET+16(%r15)
+    std  %f7,FP_OFFSET+24(%r15)
+    # Save LR as PC
+    stg  %r14,PC_OFFSET(%r15)
+
+    # Store the SP pointing to the old context-data into R0
+    lgr  %r0,%r15
+
+    # Get the SP pointing to the new context-data
+    # Note: Since the return type of the jump_fcontext is struct whose
+    # size is more than 8. The compiler automatically passes the 
+    # address of the transfer_t where the data needs to store into R2.
+
+    # Hence the first param passed to the jump_fcontext which represent
+    # the fctx we want to switch to is present in R3
+    # R2 --> Address of the return transfer_t struct
+    # R3 --> Context we want to switch to
+    # R4 --> Data
+    lgr  %r15,%r3
+
+    # Load the registers with the data present in context-data of the
+    # context we are going to switch to
+    lmg  %r6,%r15,GR_OFFSET(%r15)
+
+    # Restore Floating point registers
+    ld	 %f1,FP_OFFSET(%r15)
+    ld	 %f3,FP_OFFSET+8(%r15)
+    ld	 %f5,FP_OFFSET+16(%r15)
+    ld	 %f7,FP_OFFSET+24(%r15)
+
+    # Skip PC
+
+    # Adjust the stack
+    aghi %r15,L_CTX
+
+    # R2 --> Address where the return transfer_t is stored
+    # R0 --> FCTX
+    # R4 --> DATA
+    # R5 --> Context function
+
+    # Store the elements to return transfer_t
+    stg  %r15, 0(%r2)
+    stg  %r4, 8(%r2)
+
+    # Note: The address in R2 points to the place where the return
+    # transfer_t is stored. Since context_function take transfer_t
+    # as first parameter. And R2 is the register which holds the
+    # first parameter value.
+
+    #jump to context function
+    br 	%r5
+
+.size   ontop_fcontext,.-ontop_fcontext
+# Mark that we don't need executable stack.
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_gas.asm b/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_gas.asm
new file mode 100644
index 0000000..02e040c
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_gas.asm
@@ -0,0 +1,211 @@
+/*
+            Copyright Oliver Kowalke 2009.
+            Copyright Thomas Sailer 2013.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/*************************************************************************************
+* ---------------------------------------------------------------------------------- *
+* |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   | *
+* ---------------------------------------------------------------------------------- *
+* |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   | *
+* ---------------------------------------------------------------------------------- *
+* |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  | *
+* ---------------------------------------------------------------------------------- *
+* |                          SEE registers (XMM6-XMM15)                            | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  | *
+* ---------------------------------------------------------------------------------- *
+* | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  | *
+* ---------------------------------------------------------------------------------- *
+* |        limit      |         base       |         R12       |         R13       | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   | *
+* ---------------------------------------------------------------------------------- *
+* |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  | *
+* ---------------------------------------------------------------------------------- *
+* |        R14        |         R15        |         RDI       |        RSI        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  | *
+* ---------------------------------------------------------------------------------- *
+* |        RBX        |         RBP        |       hidden      |        RIP        | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  | *
+* ---------------------------------------------------------------------------------- *
+* |                                   parameter area                               | *
+* ---------------------------------------------------------------------------------- *
+* ---------------------------------------------------------------------------------- *
+* |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   | *
+* ---------------------------------------------------------------------------------- *
+* |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  | *
+* ---------------------------------------------------------------------------------- *
+* |       FCTX        |        DATA        |                                       | *
+* ---------------------------------------------------------------------------------- *
+**************************************************************************************/
+
+.file	"ontop_x86_64_ms_pe_gas.asm"
+.text
+.p2align 4,,15
+.globl	ontop_fcontext
+.def	ontop_fcontext;	.scl	2;	.type	32;	.endef
+.seh_proc	ontop_fcontext
+ontop_fcontext:
+.seh_endprologue
+
+    leaq  -0x118(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    /* save XMM storage */
+    movaps  %xmm6, 0x0(%rsp)
+    movaps  %xmm7, 0x10(%rsp)
+    movaps  %xmm8, 0x20(%rsp)
+    movaps  %xmm9, 0x30(%rsp)
+    movaps  %xmm10, 0x40(%rsp)
+    movaps  %xmm11, 0x50(%rsp)
+    movaps  %xmm12, 0x60(%rsp)
+    movaps  %xmm13, 0x70(%rsp)
+    movaps  %xmm14, 0x80(%rsp)
+    movaps  %xmm15, 0x90(%rsp)
+    stmxcsr  0xa0(%rsp)  /* save MMX control- and status-word */
+    fnstcw   0xa4(%rsp)  /* save x87 control-word */
+#endif
+
+    /* load NT_TIB */
+    movq  %gs:(0x30), %r10
+    /* save fiber local storage */
+    movq  0x20(%r10), %rax
+    movq  %rax, 0xb0(%rsp)
+    /* save current deallocation stack */
+    movq  0x1478(%r10), %rax
+    movq  %rax, 0xb8(%rsp)
+    /* save current stack limit */
+    movq  0x10(%r10), %rax
+    movq  %rax, 0xc0(%rsp)
+    /* save current stack base */
+    movq  0x08(%r10), %rax
+    movq  %rax, 0xc8(%rsp)
+
+    movq  %r12, 0xd0(%rsp)  /* save R12 */
+    movq  %r13, 0xd8(%rsp)  /* save R13 */
+    movq  %r14, 0xe0(%rsp)  /* save R14 */
+    movq  %r15, 0xe8(%rsp)  /* save R15 */
+    movq  %rdi, 0xf0(%rsp)  /* save RDI */
+    movq  %rsi, 0xf8(%rsp)  /* save RSI */
+    movq  %rbx, 0x100(%rsp)  /* save RBX */
+    movq  %rbp, 0x108(%rsp)  /* save RBP */
+
+    movq  %rcx, 0x110(%rsp)  /* save hidden address of transport_t */
+
+    /* preserve RSP (pointing to context-data) in RCX */
+    movq  %rsp, %rcx
+
+    /* restore RSP (pointing to context-data) from RDX */
+    movq  %rdx, %rsp
+
+#if !defined(BOOST_USE_TSX)
+    /* restore XMM storage */
+    movaps  0x0(%rsp), %xmm6
+    movaps  0x10(%rsp), %xmm7
+    movaps  0x20(%rsp), %xmm8
+    movaps  0x30(%rsp), %xmm9
+    movaps  0x40(%rsp), %xmm10
+    movaps  0x50(%rsp), %xmm11
+    movaps  0x60(%rsp), %xmm12
+    movaps  0x70(%rsp), %xmm13
+    movaps  0x80(%rsp), %xmm14
+    movaps  0x90(%rsp), %xmm15
+ 	ldmxcsr 0xa0(%rsp) /* restore MMX control- and status-word */
+ 	fldcw   0xa4(%rsp) /* restore x87 control-word */
+#endif
+
+    /* load NT_TIB */
+    movq  %gs:(0x30), %r10
+    /* restore fiber local storage */
+    movq  0xb0(%rsp), %rax
+    movq  %rax, 0x20(%r10)
+    /* restore current deallocation stack */
+    movq  0xb8(%rsp), %rax
+    movq  %rax, 0x1478(%r10)
+    /* restore current stack limit */
+    movq  0xc0(%rsp), %rax
+    movq  %rax, 0x10(%r10)
+    /* restore current stack base */
+    movq  0xc8(%rsp), %rax
+    movq  %rax, 0x08(%r10)
+
+    movq  0xd0(%rsp),  %r12  /* restore R12 */
+    movq  0xd8(%rsp),  %r13  /* restore R13 */
+    movq  0xe0(%rsp),  %r14  /* restore R14 */
+    movq  0xe8(%rsp),  %r15  /* restore R15 */
+    movq  0xf0(%rsp),  %rdi  /* restore RDI */
+    movq  0xf8(%rsp),  %rsi  /* restore RSI */
+    movq  0x100(%rsp), %rbx  /* restore RBX */
+    movq  0x108(%rsp), %rbp  /* restore RBP */
+
+    movq  0x110(%rsp), %rax  /* restore hidden address of transport_t */
+
+    leaq  0x118(%rsp), %rsp /* prepare stack */
+
+    /* keep return-address on stack */
+
+    /* transport_t returned in RAX */
+    /* return parent fcontext_t */
+    movq  %rcx, 0x0(%rax)
+    /* return data */
+    movq  %r8, 0x8(%rax)
+
+    /* transport_t as 1.arg of context-function */
+    /* RCX contains address of returned (hidden) transfer_t */
+    movq  %rax, %rcx
+    /* RDX contains address of passed transfer_t */
+    movq  %rax, %rdx
+
+    /* indirect jump to context */
+    jmp  *%r9
+.seh_endproc
+
+.section .drectve
+.ascii " -export:\"ontop_fcontext\""
diff --git a/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_masm.asm b/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_masm.asm
new file mode 100644
index 0000000..b57dd15
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_x86_64_ms_pe_masm.asm
@@ -0,0 +1,207 @@
+
+;           Copyright Oliver Kowalke 2009.
+;  Distributed under the Boost Software License, Version 1.0.
+;     (See accompanying file LICENSE_1_0.txt or copy at
+;           http://www.boost.org/LICENSE_1_0.txt)
+
+;  ----------------------------------------------------------------------------------
+;  |     0   |     1   |     2    |     3   |     4   |     5   |     6   |     7   |
+;  ----------------------------------------------------------------------------------
+;  |    0x0  |    0x4  |    0x8   |    0xc  |   0x10  |   0x14  |   0x18  |   0x1c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |     8   |    9    |    10    |    11   |    12   |    13   |    14   |    15   |
+;  ----------------------------------------------------------------------------------
+;  |   0x20  |  0x24   |   0x28   |   0x2c  |   0x30  |   0x34  |   0x38  |   0x3c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    16   |    17   |    18   |    19    |    20   |    21   |    22   |    23   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe40  |   0x44 |   0x48  |   0x4c   |   0x50  |   0x54  |   0x58  |   0x5c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    24   |   25    |    26    |   27    |    28   |    29   |    30   |    31   |
+;  ----------------------------------------------------------------------------------
+;  |   0x60  |   0x64  |   0x68   |   0x6c  |   0x70  |   0x74  |   0x78  |   0x7c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    32   |   32    |    33    |   34    |    35   |    36   |    37   |    38   |
+;  ----------------------------------------------------------------------------------
+;  |   0x80  |   0x84  |   0x88   |   0x8c  |   0x90  |   0x94  |   0x98  |   0x9c  |
+;  ----------------------------------------------------------------------------------
+;  |                          SEE registers (XMM6-XMM15)                            |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    39   |   40    |    41    |   42    |    43   |    44   |    45   |    46   |
+;  ----------------------------------------------------------------------------------
+;  |   0xa0  |   0xa4  |   0xa8   |   0xac  |   0xb0  |   0xb4  |   0xb8  |   0xbc  |
+;  ----------------------------------------------------------------------------------
+;  | fc_mxcsr|fc_x87_cw|     <alignment>    |       fbr_strg    |      fc_dealloc   |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    47   |   48    |    49    |   50    |    51   |    52   |    53   |    54   |
+;  ----------------------------------------------------------------------------------
+;  |   0xc0  |   0xc4  |   0xc8   |   0xcc  |   0xd0  |   0xd4  |   0xd8  |   0xdc  |
+;  ----------------------------------------------------------------------------------
+;  |        limit      |         base       |         R12       |         R13       |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    55   |   56    |    57    |   58    |    59   |    60   |    61   |    62   |
+;  ----------------------------------------------------------------------------------
+;  |   0xe0  |   0xe4  |   0xe8   |   0xec  |   0xf0  |   0xf4  |   0xf8  |   0xfc  |
+;  ----------------------------------------------------------------------------------
+;  |        R14        |         R15        |         RDI       |        RSI        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    63   |   64    |    65    |   66    |    67   |    68   |    69   |    70   |
+;  ----------------------------------------------------------------------------------
+;  |  0x100  |  0x104  |  0x108   |  0x10c  |  0x110  |  0x114  |  0x118  |  0x11c  |
+;  ----------------------------------------------------------------------------------
+;  |        RBX        |         RBP        |       hidden      |        RIP        |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    71   |   72    |    73    |   74    |    75   |    76   |    77   |    78   |
+;  ----------------------------------------------------------------------------------
+;  |  0x120  |  0x124  |  0x128   |  0x12c  |  0x130  |  0x134  |  0x138  |  0x13c  |
+;  ----------------------------------------------------------------------------------
+;  |                                   parameter area                               |
+;  ----------------------------------------------------------------------------------
+;  ----------------------------------------------------------------------------------
+;  |    79   |   80    |    81    |   82    |    83   |    84   |    85   |    86   |
+;  ----------------------------------------------------------------------------------
+;  |  0x140  |  0x144  |  0x148   |  0x14c  |  0x150  |  0x154  |  0x158  |  0x15c  |
+;  ----------------------------------------------------------------------------------
+;  |       FCTX        |        DATA        |                                       |
+;  ----------------------------------------------------------------------------------
+
+.code
+
+ontop_fcontext PROC BOOST_CONTEXT_EXPORT FRAME
+    .endprolog
+
+    ; prepare stack
+    lea rsp, [rsp-0118h]
+
+IFNDEF BOOST_USE_TSX
+    ; save XMM storage
+    movaps  [rsp], xmm6
+    movaps  [rsp+010h], xmm7
+    movaps  [rsp+020h], xmm8
+    movaps  [rsp+030h], xmm9
+    movaps  [rsp+040h], xmm10
+    movaps  [rsp+050h], xmm11
+    movaps  [rsp+060h], xmm12
+    movaps  [rsp+070h], xmm13
+    movaps  [rsp+080h], xmm14
+    movaps  [rsp+090h], xmm15
+    ; save MMX control- and status-word
+    stmxcsr  [rsp+0a0h]
+    ; save x87 control-word
+    fnstcw  [rsp+0a4h]
+ENDIF
+
+    ; load NT_TIB
+    mov  r10,  gs:[030h]
+    ; save fiber local storage
+    mov  rax, [r10+020h]
+    mov  [rsp+0b0h], rax
+    ; save current deallocation stack
+    mov  rax, [r10+01478h]
+    mov  [rsp+0b8h], rax
+    ; save current stack limit
+    mov  rax, [r10+010h]
+    mov  [rsp+0c0h], rax
+    ; save current stack base
+    mov  rax,  [r10+08h]
+    mov  [rsp+0c8h], rax
+
+    mov [rsp+0d0h], r12  ; save R12
+    mov [rsp+0d8h], r13  ; save R13
+    mov [rsp+0e0h], r14  ; save R14
+    mov [rsp+0e8h], r15  ; save R15
+    mov [rsp+0f0h], rdi  ; save RDI
+    mov [rsp+0f8h], rsi  ; save RSI
+    mov [rsp+0100h], rbx  ; save RBX
+    mov [rsp+0108h], rbp  ; save RBP
+
+    mov [rsp+0110h], rcx  ; save hidden address of transport_t
+
+    ; preserve RSP (pointing to context-data) in RCX
+    mov  rcx, rsp
+
+    ; restore RSP (pointing to context-data) from RDX
+    mov  rsp, rdx
+
+IFNDEF BOOST_USE_TSX
+    ; restore XMM storage
+    movaps  xmm6, [rsp]
+    movaps  xmm7, [rsp+010h]
+    movaps  xmm8, [rsp+020h]
+    movaps  xmm9, [rsp+030h]
+    movaps  xmm10, [rsp+040h]
+    movaps  xmm11, [rsp+050h]
+    movaps  xmm12, [rsp+060h]
+    movaps  xmm13, [rsp+070h]
+    movaps  xmm14, [rsp+080h]
+    movaps  xmm15, [rsp+090h]
+    ; restore MMX control- and status-word
+    ldmxcsr  [rsp+0a0h]
+    ; save x87 control-word
+    fldcw   [rsp+0a4h]
+ENDIF
+
+    ; load NT_TIB
+    mov  r10,  gs:[030h]
+    ; restore fiber local storage
+    mov  rax, [rsp+0b0h]
+    mov  [r10+020h], rax
+    ; restore current deallocation stack
+    mov  rax, [rsp+0b8h]
+    mov  [r10+01478h], rax
+    ; restore current stack limit
+    mov  rax, [rsp+0c0h]
+    mov  [r10+010h], rax
+    ; restore current stack base
+    mov  rax, [rsp+0c8h]
+    mov  [r10+08h], rax
+
+    mov r12, [rsp+0d0h]  ; restore R12
+    mov r13, [rsp+0d8h]  ; restore R13
+    mov r14, [rsp+0e0h]  ; restore R14
+    mov r15, [rsp+0e8h]  ; restore R15
+    mov rdi, [rsp+0f0h]  ; restore RDI
+    mov rsi, [rsp+0f8h]  ; restore RSI
+    mov rbx, [rsp+0100h]  ; restore RBX
+    mov rbp, [rsp+0108h]  ; restore RBP
+
+    mov rax, [rsp+0110h] ; restore hidden address of transport_t
+
+    ; prepare stack
+    lea rsp, [rsp+0118h]
+
+    ; keep return-address on stack
+
+    ; transport_t returned in RAX
+    ; return parent fcontext_t
+    mov  [rax], rcx
+    ; return data
+    mov  [rax+08h], r8
+
+    ; transport_t as 1.arg of context-function
+    ; RCX contains address of returned (hidden) transfer_t
+    mov rcx,  rax  
+    ; RDX contains address of passed transfer_t
+    mov rdx,  rax
+
+    ; indirect jump to context
+    jmp  r9
+ontop_fcontext ENDP
+END
diff --git a/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_elf_gas.S b/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_elf_gas.S
new file mode 100644
index 0000000..447a1ec
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_elf_gas.S
@@ -0,0 +1,84 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.file "ontop_x86_64_sysv_elf_gas.S"
+.text
+.globl ontop_fcontext
+.type ontop_fcontext,@function
+.align 16
+ontop_fcontext:
+    /* preserve ontop-function in R8 */
+    movq  %rdx, %r8
+
+    leaq  -0x38(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%rsp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%rsp)  /* save x87 control-word */
+#endif
+
+    movq  %r12, 0x8(%rsp)  /* save R12 */
+    movq  %r13, 0x10(%rsp)  /* save R13 */
+    movq  %r14, 0x18(%rsp)  /* save R14 */
+    movq  %r15, 0x20(%rsp)  /* save R15 */
+    movq  %rbx, 0x28(%rsp)  /* save RBX */
+    movq  %rbp, 0x30(%rsp)  /* save RBP */
+
+    /* store RSP (pointing to context-data) in RAX */
+    movq  %rsp, %rax
+
+    /* restore RSP (pointing to context-data) from RDI */
+    movq  %rdi, %rsp
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%rsp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%rsp)  /* restore x87 control-word */
+#endif
+
+    movq  0x8(%rsp), %r12  /* restore R12 */
+    movq  0x10(%rsp), %r13  /* restore R13 */
+    movq  0x18(%rsp), %r14  /* restore R14 */
+    movq  0x20(%rsp), %r15  /* restore R15 */
+    movq  0x28(%rsp), %rbx  /* restore RBX */
+    movq  0x30(%rsp), %rbp  /* restore RBP */
+
+    leaq  0x38(%rsp), %rsp /* prepare stack */
+
+    /* return transfer_t from jump */
+    /* RAX == fctx, RDX == data */
+    movq  %rsi, %rdx
+    /* pass transfer_t as first arg in context function */
+    /* RDI == fctx, RSI == data */
+    movq  %rax, %rdi
+
+    /* keep return-address on stack */
+
+    /* indirect jump to context */
+    jmp  *%r8
+.size ontop_fcontext,.-ontop_fcontext
+
+/* Mark that we don't need executable stack.  */
+.section .note.GNU-stack,"",%progbits
diff --git a/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_macho_gas.S b/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_macho_gas.S
new file mode 100644
index 0000000..49755c6
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/ontop_x86_64_sysv_macho_gas.S
@@ -0,0 +1,78 @@
+/*
+            Copyright Oliver Kowalke 2009.
+   Distributed under the Boost Software License, Version 1.0.
+      (See accompanying file LICENSE_1_0.txt or copy at
+            http://www.boost.org/LICENSE_1_0.txt)
+*/
+
+/****************************************************************************************
+ *                                                                                      *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    0    |    1    |    2    |    3    |    4     |    5    |    6    |    7    |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x0   |   0x4   |   0x8   |   0xc   |   0x10   |   0x14  |   0x18  |   0x1c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  | fc_mxcsr|fc_x87_cw|        R12        |         R13        |        R14        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |    8    |    9    |   10    |   11    |    12    |    13   |    14   |    15   |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |   0x20  |   0x24  |   0x28  |  0x2c   |   0x30   |   0x34  |   0x38  |   0x3c  |  *
+ *  ----------------------------------------------------------------------------------  *
+ *  |        R15        |        RBX        |         RBP        |        RIP        |  *
+ *  ----------------------------------------------------------------------------------  *
+ *                                                                                      *
+ ****************************************************************************************/
+
+.text
+.globl _ontop_fcontext
+.align 8
+_ontop_fcontext:
+    /* preserve ontop-function in R8 */
+    movq  %rdx, %r8
+
+    leaq  -0x38(%rsp), %rsp /* prepare stack */
+
+#if !defined(BOOST_USE_TSX)
+    stmxcsr  (%rsp)     /* save MMX control- and status-word */
+    fnstcw   0x4(%rsp)  /* save x87 control-word */
+#endif
+
+    movq  %r12, 0x8(%rsp)  /* save R12 */
+    movq  %r13, 0x10(%rsp)  /* save R13 */
+    movq  %r14, 0x18(%rsp)  /* save R14 */
+    movq  %r15, 0x20(%rsp)  /* save R15 */
+    movq  %rbx, 0x28(%rsp)  /* save RBX */
+    movq  %rbp, 0x30(%rsp)  /* save RBP */
+
+    /* store RSP (pointing to context-data) in RAX */
+    movq  %rsp, %rax
+
+    /* restore RSP (pointing to context-data) from RDI */
+    movq  %rdi, %rsp
+
+#if !defined(BOOST_USE_TSX)
+    ldmxcsr  (%rsp)     /* restore MMX control- and status-word */
+    fldcw    0x4(%rsp)  /* restore x87 control-word */
+#endif
+
+    movq  0x8(%rsp), %r12  /* restore R12 */
+    movq  0x10(%rsp), %r13  /* restore R13 */
+    movq  0x18(%rsp), %r14  /* restore R14 */
+    movq  0x20(%rsp), %r15  /* restore R15 */
+    movq  0x28(%rsp), %rbx  /* restore RBX */
+    movq  0x30(%rsp), %rbp  /* restore RBP */
+
+    leaq  0x38(%rsp), %rsp /* prepare stack */
+
+    /* return transfer_t from jump */
+    /* RAX == fctx, RDX == data */
+    movq  %rsi, %rdx
+    /* pass transfer_t as first arg in context function */
+    /* RDI == fctx, RSI == data */
+    movq  %rax, %rdi
+
+    /* keep return-address on stack */
+
+    /* indirect jump to context */
+    jmp  *%r8
diff --git a/lib/context_switcher/asm/fcontext/tail_ppc32_sysv_elf_gas.cpp b/lib/context_switcher/asm/fcontext/tail_ppc32_sysv_elf_gas.cpp
new file mode 100644
index 0000000..3486084
--- /dev/null
+++ b/lib/context_switcher/asm/fcontext/tail_ppc32_sysv_elf_gas.cpp
@@ -0,0 +1,18 @@
+
+//          Copyright Oliver Kowalke 2009.
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//        http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/context/detail/fcontext.hpp>
+
+using boost::context::detail::fcontext_t;
+using boost::context::detail::transfer_t;
+
+// This C++ tail of ontop_fcontext() allocates transfer_t{ from, vp }
+// on the stack.  If fn() throws a C++ exception, then the C++ runtime
+// must remove this tail's stack frame.
+extern "C" transfer_t
+ontop_fcontext_tail( int ignore, void * vp, transfer_t (* fn)(transfer_t), fcontext_t const from) {
+    return fn( transfer_t{ from, vp });
+}
diff --git a/lib/context_switcher/asm/switch_context_arm32.s b/lib/context_switcher/asm/switch_context_arm32.s
deleted file mode 100644
index 29d1831..0000000
--- a/lib/context_switcher/asm/switch_context_arm32.s
+++ /dev/null
@@ -1,38 +0,0 @@
-	.arm
-	.text
-	.global	__cs_switch_context
-	.type	__cs_switch_context, %function
-
-__cs_switch_context:
-        /* Parameter List (in order)
-        * r0 = pointer to continuation (should hold value of target stack will be filled with this continuation)
-        *
-        * Return
-        * r0 = continuation that returned control back to the caller (null if fallthrough)
-        *
-        * Variables
-        * r1 = temporary for the old stack pointer */
-
-        /* ========== Save State ========== */
-        /* store programm counter for later return */
-        push {lr}
-        /* store callee saved registers */
-        push {r4-r12,lr}
-        /* ========== Save State ========== */
-
-        /* Perform change to new stack */
-        /* Keep old stack as result from this function. */
-        mov r1, sp
-        /* Switch to new stack pointer. */
-        mov sp, r0
-
-
-        /* ========== Restore State ========== */
-        /* restore callee saved registers */
-        pop {r4-r12,lr}
-        /* ========== Restore State ========== */
-
-        /* Just return back from the call. */
-        /* This is the end of a fiber, so we have no continuation. */
-        mov r0, r1
-        pop {pc}
diff --git a/lib/context_switcher/include/context_switcher/context.h b/lib/context_switcher/include/context_switcher/context.h
new file mode 100644
index 0000000..d35eac8
--- /dev/null
+++ b/lib/context_switcher/include/context_switcher/context.h
@@ -0,0 +1,25 @@
+
+#ifndef CONTEXT_SWITCHER_CONTEXT_H_
+#define CONTEXT_SWITCHER_CONTEXT_H_
+
+#ifdef CS_USE_CSCONTEXT
+#include "cscontext.h"
+#else
+#include "fcontext.h"
+#endif
+
+namespace context_switcher {
+
+#ifdef CS_USE_CSCONTEXT
+using continuation_t = cscontext::continuation_t;
+using stack_pointer_t = cscontext::stack_pointer_t;
+using callback_t = cscontext::callback_t;
+#else
+using continuation_t = fcontext::continuation_t;
+using stack_pointer_t = fcontext::stack_pointer_t;
+using callback_t = fcontext::callback_t;
+#endif
+
+}
+
+#endif //CONTEXT_SWITCHER_CONTEXT_H_
diff --git a/lib/context_switcher/include/context_switcher/context_switcher.h b/lib/context_switcher/include/context_switcher/context_switcher.h
index 0e1be46..57c6bf6 100644
--- a/lib/context_switcher/include/context_switcher/context_switcher.h
+++ b/lib/context_switcher/include/context_switcher/context_switcher.h
@@ -6,26 +6,58 @@
 #include <cstdint>
 #include <new>
 
-#include "assembly_bindings.h"
+#include "context.h"
+
 #include "continuation.h"
 #include "lambda_capture.h"
 
+#ifdef THREAD_SANITIZER
+#include "tsan_fiber_api.h"
+#endif
+
 namespace context_switcher {
 
+continuation switch_context(continuation &&cont);
+
 template<typename F>
-continuation enter_context(assembly_bindings::stack_pointer_t stack_memory, size_t stack_size, F &&lambda) {
-  assembly_bindings::stack_pointer_t lambda_memory = stack_memory + stack_size - sizeof(lambda_capture<F>);
+continuation enter_context(stack_pointer_t stack_memory, size_t stack_size, F &&lambda) {
+  stack_pointer_t lambda_memory = stack_memory + stack_size - sizeof(lambda_capture<F>);
   auto *captured_lambda = place_lambda_capture(std::forward<F>(lambda), lambda_memory);
 
-  assembly_bindings::stack_pointer_t stack_base = lambda_memory;
-  assembly_bindings::stack_pointer_t stack_limit = stack_memory;
-
-  assembly_bindings::callback_t callback = lambda_capture_callback<lambda_capture<F>>;
-  return continuation{assembly_bindings::__cs_enter_context(stack_base, captured_lambda, callback, stack_limit)};
+  stack_pointer_t stack_base = lambda_memory - 64;
+  stack_pointer_t stack_limit = stack_memory;
+
+#ifdef CS_USE_CSCONTEXT
+  cscontext::callback_t callback = lambda_capture_callback<lambda_capture<F>>;
+
+  void *result = cscontext::__cs_enter_context(stack_base, captured_lambda, callback, stack_limit);
+  return continuation{result};
+#else // CS_USE_CSCONTEXT
+  fcontext::callback_t callback = lambda_capture_callback<lambda_capture<F>>;
+  fcontext::continuation_t new_context = fcontext::make_fcontext(stack_base, stack_base - stack_limit, callback);
+#ifdef THREAD_SANITIZER
+  void *new_fiber = __tsan_create_fiber(0);
+  void *old_fiber = __tsan_get_current_fiber();
+  captured_lambda->my_tsan_fiber_ = new_fiber;
+  captured_lambda->previous_tsan_fiber_ = old_fiber;
+  __tsan_switch_to_fiber(new_fiber, 0);
+  fcontext::transfer_t transfer = fcontext::jump_fcontext(new_context, captured_lambda);
+  if (transfer.data) {
+    return continuation{transfer.continuation, transfer.data};
+  } else {
+    return continuation{nullptr, nullptr};
+  }
+#else
+  fcontext::transfer_t transfer = fcontext::jump_fcontext(new_context, captured_lambda);
+  if (transfer.data) {
+    return continuation{transfer.continuation};
+  } else {
+    return continuation{nullptr};
+  }
+#endif // THREAD_SANITIZER
+#endif // CS_USE_CSCONTEXT
 }
 
-continuation switch_context(continuation &&cont);
-
 }
 
 #endif //CONTEXT_SWITCHER_CONTEXT_SWITCHER_H_
diff --git a/lib/context_switcher/include/context_switcher/continuation.h b/lib/context_switcher/include/context_switcher/continuation.h
index 63bc7e1..ff6c31c 100644
--- a/lib/context_switcher/include/context_switcher/continuation.h
+++ b/lib/context_switcher/include/context_switcher/continuation.h
@@ -2,7 +2,7 @@
 #ifndef CONTEXT_SWITCHER_CONTINUATION_H_
 #define CONTEXT_SWITCHER_CONTINUATION_H_
 
-#include "assembly_bindings.h"
+#include "context.h"
 
 #include <cstdlib>
 #include <cstdio>
@@ -17,21 +17,30 @@ namespace context_switcher {
  */
 struct continuation {
  public:
-  continuation() : cont_pointer_{nullptr} {};
-  explicit continuation(assembly_bindings::continuation_t cont_pointer) : cont_pointer_{cont_pointer} {};
+  continuation() = default;
+#ifdef THREAD_SANITIZER
+  continuation(continuation_t cont_pointer, void *tsan_fiber) : cont_pointer_{cont_pointer}, tsan_fiber_{tsan_fiber} {};
+#else
+  explicit continuation(continuation_t cont_pointer) : cont_pointer_{cont_pointer} {};
+#endif
 
   // Move-Only Semantics
   continuation(const continuation &other) = delete;
   continuation(continuation &&other) noexcept {
     cont_pointer_ = other.cont_pointer_;
     other.cont_pointer_ = nullptr;
+#ifdef THREAD_SANITIZER
+    tsan_fiber_ = other.tsan_fiber_;
+#endif
   }
 
   continuation &operator=(const continuation &other) = delete;
   continuation &operator=(continuation &&other) noexcept {
     cont_pointer_ = other.cont_pointer_;
     other.cont_pointer_ = nullptr;
-
+#ifdef THREAD_SANITIZER
+    tsan_fiber_ = other.tsan_fiber_;
+#endif
     return *this;
   }
 
@@ -40,7 +49,7 @@ struct continuation {
     return cont_pointer_ != nullptr;
   }
 
-  assembly_bindings::continuation_t consume() {
+  continuation_t consume() {
     if (cont_pointer_ == nullptr) {
       printf("Error!\n");
     }
@@ -50,8 +59,17 @@ struct continuation {
     return tmp;
   }
 
+#ifdef THREAD_SANITIZER
+  void *get_tsan_fiber() {
+    return tsan_fiber_;
+  }
+#endif
+
  private:
-  assembly_bindings::continuation_t cont_pointer_;
+  continuation_t cont_pointer_{nullptr};
+#ifdef THREAD_SANITIZER
+  void *tsan_fiber_{nullptr};
+#endif
 };
 
 }
diff --git a/lib/context_switcher/include/context_switcher/assembly_bindings.h b/lib/context_switcher/include/context_switcher/cscontext.h
similarity index 94%
rename from lib/context_switcher/include/context_switcher/assembly_bindings.h
rename to lib/context_switcher/include/context_switcher/cscontext.h
index e87576f..120b05c 100644
--- a/lib/context_switcher/include/context_switcher/assembly_bindings.h
+++ b/lib/context_switcher/include/context_switcher/cscontext.h
@@ -5,6 +5,7 @@
 /**
  * Low level bindings to the two assembly functions used to switch context.
  * Can be used standalone to build new control structures, but should be handled with care.
+ * This is the API to the cscontext version (favoring fast creating of coroutines/short running contexts).
  *
  * Basic usage:
  * // Switch control to a new stack.
@@ -16,7 +17,7 @@
  */
 
 namespace context_switcher {
-namespace assembly_bindings {
+namespace cscontext {
 
 using continuation_t = void *;
 using stack_pointer_t = char *;
diff --git a/lib/context_switcher/include/context_switcher/fcontext.h b/lib/context_switcher/include/context_switcher/fcontext.h
new file mode 100644
index 0000000..474d779
--- /dev/null
+++ b/lib/context_switcher/include/context_switcher/fcontext.h
@@ -0,0 +1,36 @@
+#ifndef CONTEXT_SWITCHER_FCONTEXT_H_
+#define CONTEXT_SWITCHER_FCONTEXT_H_
+
+#include <cstdint>
+#include <cstddef>
+
+/**
+ * Low level bindings to the two assembly functions used to switch context.
+ * Can be used standalone to build new control structures, but should be handled with care.
+ * This is the API to the fcontext (boost.context assembly).
+ */
+
+namespace context_switcher {
+namespace fcontext {
+
+using continuation_t = void *;
+using stack_pointer_t = char *;
+
+struct transfer_t {
+  continuation_t continuation;
+  void *data;
+};
+
+using callback_t = void (*)(transfer_t);
+
+extern "C" {
+transfer_t jump_fcontext(continuation_t cont, void *data);
+continuation_t make_fcontext(stack_pointer_t sp, size_t size, callback_t corofn);
+
+transfer_t ontop_fcontext(continuation_t cont, void *data, transfer_t(*fn)(transfer_t));
+}
+
+}
+}
+
+#endif //CONTEXT_SWITCHER_FCONTEXT_H_
diff --git a/lib/context_switcher/include/context_switcher/lambda_capture.h b/lib/context_switcher/include/context_switcher/lambda_capture.h
index c4c452e..072a4b4 100644
--- a/lib/context_switcher/include/context_switcher/lambda_capture.h
+++ b/lib/context_switcher/include/context_switcher/lambda_capture.h
@@ -6,9 +6,11 @@
 #include <new>
 #include <type_traits>
 
-#include "assembly_bindings.h"
+#include "context.h"
 #include "continuation.h"
 
+#include "tsan_fiber_api.h"
+
 /**
  * Helpers to more easily use a lambda expression as the code run on a context switch.
  * Captures lambdas by placing them in a memory region and offering a conversion form
@@ -22,26 +24,57 @@ struct lambda_capture {
   template<typename FARG>
   explicit lambda_capture(FARG &&lambda) : lambda_{std::forward<FARG>(lambda)} {}
 
-  assembly_bindings::continuation_t operator()(assembly_bindings::continuation_t continuation_pointer) {
-    continuation cont = lambda_(continuation{continuation_pointer});
-    return cont.consume();
+#ifdef THREAD_SANITIZER
+  continuation operator()(continuation_t cont) {
+    return lambda_(continuation{cont, previous_tsan_fiber_});
+  }
+  void *previous_tsan_fiber_;
+  void *my_tsan_fiber_;
+#else
+  continuation operator()(continuation_t cont) {
+    return lambda_(continuation{cont});
   }
+#endif
 
  private:
   F lambda_;
 };
 
+#ifdef CS_USE_CSCONTEXT
 template<typename T>
-assembly_bindings::continuation_t lambda_capture_callback(assembly_bindings::continuation_t continuation_pointer,
-                                                          void *lambda_capture_param) {
+cscontext::continuation_t lambda_capture_callback(cscontext::continuation_t continuation_pointer,
+                                                  void *lambda_capture_param) {
   // Perform Call
   T *lambda_capture = reinterpret_cast<T *>(lambda_capture_param);
-  auto result_continuation = (*lambda_capture)(continuation_pointer);
+  continuation cont = (*lambda_capture)(continuation_pointer);
 
   // Free resources and switch to result_continuation (this execution thread is finished with the return)
   lambda_capture->~T();
-  return result_continuation;
+  return cont.consume();
+}
+#else // CS_USE_CSCONTEXT
+continuation switch_context(continuation &&cont);
+template<typename T>
+void lambda_capture_callback(fcontext::transfer_t transfer) {
+  // Perform Call
+  T *lambda_capture = reinterpret_cast<T *>(transfer.data);
+  continuation cont = (*lambda_capture)(transfer.continuation);
+
+  // Free resources and switch to result_continuation (this execution thread is finished with the return)
+  lambda_capture->~T();
+
+#ifdef THREAD_SANITIZER
+  continuation_t cont_pointer = cont.consume();
+  void *next_fiber = cont.get_tsan_fiber();
+  __tsan_switch_to_fiber(next_fiber, 0);
+  __tsan_destroy_fiber(lambda_capture->my_tsan_fiber_);
+  fcontext::jump_fcontext(cont_pointer, (void*)0);
+#else // THREAD_SANITIZER
+  continuation_t cont_pointer = cont.consume();
+  fcontext::jump_fcontext(cont_pointer, (void *) 0);
+#endif // THREAD_SANITIZER
 }
+#endif // CS_USE_CSCONTEXT
 
 template<typename F>
 static lambda_capture<typename std::remove_reference<F>::type> *place_lambda_capture(F &&lambda, char *memory) {
diff --git a/lib/context_switcher/include/context_switcher/tsan_fiber_api.h b/lib/context_switcher/include/context_switcher/tsan_fiber_api.h
new file mode 100644
index 0000000..04df6f0
--- /dev/null
+++ b/lib/context_switcher/include/context_switcher/tsan_fiber_api.h
@@ -0,0 +1,21 @@
+
+#ifndef PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_
+#define PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_
+
+extern "C" {
+// Fiber switching API.
+//   - TSAN context for fiber can be created by __tsan_create_fiber
+//     and freed by __tsan_destroy_fiber.
+//   - TSAN context of current fiber or thread can be obtained
+//     by calling __tsan_get_current_fiber.
+//   - __tsan_switch_to_fiber should be called immediatly before switch
+//     to fiber, such as call of swapcontext.
+//   - Fiber name can be set by __tsan_set_fiber_name.
+void *__tsan_get_current_fiber(void);
+void *__tsan_create_fiber(unsigned flags);
+void __tsan_destroy_fiber(void *fiber);
+void __tsan_switch_to_fiber(void *fiber, unsigned flags);
+void __tsan_set_fiber_name(void *fiber, const char *name);
+};
+
+#endif //PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_
diff --git a/lib/context_switcher/src/context_switcher.cpp b/lib/context_switcher/src/context_switcher.cpp
index 28c3cd9..93be111 100644
--- a/lib/context_switcher/src/context_switcher.cpp
+++ b/lib/context_switcher/src/context_switcher.cpp
@@ -1,11 +1,42 @@
 #include "context_switcher/context_switcher.h"
 
+#ifdef THREAD_SANITIZER
+#include "context_switcher/tsan_fiber_api.h"
+#endif
+
 namespace context_switcher {
 
+#ifdef CS_USE_CSCONTEXT
 continuation switch_context(continuation &&cont) {
-  assembly_bindings::continuation_t cont_pointer = cont.consume();
-
-  return continuation{assembly_bindings::__cs_switch_context(cont_pointer)};
+  continuation_t cont_pointer = cont.consume();
+  continuation_t result = cscontext::__cs_switch_context(cont_pointer);
+  return continuation{result};
+}
+#else
+#ifdef THREAD_SANITIZER
+continuation switch_context(continuation &&cont) {
+  continuation_t cont_pointer = cont.consume();
+  void *next_fiber = cont.get_tsan_fiber();
+  void *old_fiber = __tsan_get_current_fiber();
+  __tsan_switch_to_fiber(next_fiber, 0);
+  fcontext::transfer_t transfer = fcontext::jump_fcontext(cont_pointer, old_fiber);
+  if (transfer.data) {
+    return continuation{transfer.continuation, transfer.data};
+  } else {
+    return continuation{nullptr, 0};
+  }
+}
+#else
+continuation switch_context(continuation &&cont) {
+  continuation_t cont_pointer = cont.consume();
+  fcontext::transfer_t transfer = fcontext::jump_fcontext(cont_pointer, (void *) 1);
+  if (transfer.data) {
+    return continuation{transfer.continuation};
+  } else {
+    return continuation{nullptr};
+  }
 }
+#endif
+#endif
 
 }
diff --git a/lib/pls/include/pls/internal/base/error_handling.h b/lib/pls/include/pls/internal/base/error_handling.h
index bdb6466..d21f751 100644
--- a/lib/pls/include/pls/internal/base/error_handling.h
+++ b/lib/pls/include/pls/internal/base/error_handling.h
@@ -16,6 +16,6 @@
 void pls_error(const char *msg);
 
 // TODO: Distinguish between debug/internal asserts and production asserts.
-#define PLS_ASSERT(cond, msg) // if (!(cond)) { pls_error(msg); }
+#define PLS_ASSERT(cond, msg)  if (!(cond)) { pls_error(msg); }
 
 #endif //PLS_ERROR_HANDLING_H
diff --git a/lib/pls/include/pls/internal/helpers/tsan_fiber_api.h b/lib/pls/include/pls/internal/helpers/tsan_fiber_api.h
new file mode 100644
index 0000000..04df6f0
--- /dev/null
+++ b/lib/pls/include/pls/internal/helpers/tsan_fiber_api.h
@@ -0,0 +1,21 @@
+
+#ifndef PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_
+#define PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_
+
+extern "C" {
+// Fiber switching API.
+//   - TSAN context for fiber can be created by __tsan_create_fiber
+//     and freed by __tsan_destroy_fiber.
+//   - TSAN context of current fiber or thread can be obtained
+//     by calling __tsan_get_current_fiber.
+//   - __tsan_switch_to_fiber should be called immediatly before switch
+//     to fiber, such as call of swapcontext.
+//   - Fiber name can be set by __tsan_set_fiber_name.
+void *__tsan_get_current_fiber(void);
+void *__tsan_create_fiber(unsigned flags);
+void __tsan_destroy_fiber(void *fiber);
+void __tsan_switch_to_fiber(void *fiber, unsigned flags);
+void __tsan_set_fiber_name(void *fiber, const char *name);
+};
+
+#endif //PREDICTABLE_PARALLEL_PATTERNS_LIB_PLS_INCLUDE_PLS_INTERNAL_HELPERS_TSAN_FIBER_API_H_