.arm .text .global custom_stack_callback .type custom_stack_callback, %function.align 4custom_stack_callback: /* r0 new stack adress (passed as parameter) */ /* r4 temporary for restoring old stack (callee saved, so we get the correct value in case of a return) */ push {r4, lr} /* store the callee saved register as required and the return address */ mov r4, sp /* store current stack pointer */ mov sp, r0 /* update stack pointer to new user level stack */ bl callback /* enter next tasks (will not return if continuation is stolen) */ mov sp, r4 /* restore to the old stack pointer */ pop {r4, pc} /* restore the callee saved register as required and returns */
