coroutine/x86/Context.s


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##
##  File file is part of the "Coroutine" project and released under the MIT License.
##
##  Created by Samuel Williams on 3/11/2018.
##  Copyright, 2018, by Samuel Williams. All rights reserved.
##

.text

.globl coroutine_transfer
coroutine_transfer:

# For older linkers
.globl _coroutine_transfer
_coroutine_transfer:

	# Save caller registers
	pushl %ebp
	pushl %ebx
	pushl %edi
	pushl %esi

	# Save caller stack pointer
	movl %esp, (%ecx)

	# Restore callee stack pointer
	movl (%edx), %esp

	# Restore callee stack
	popl %esi
	popl %edi
	popl %ebx
	popl %ebp

	# Save the first argument as the return value
	movl %ecx, %eax

	# Jump to the address on the stack
	ret