libucontext/arch/arm/swapcontext.S

32 lines
1010 B
ArmAsm

/*
* Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include "defs.h"
ALIAS(swapcontext, libucontext_swapcontext)
ALIAS(__swapcontext, libucontext_swapcontext)
FUNC(libucontext_swapcontext)
/* copy all of the current registers into the ucontext structure */
add r2, r0, #REG_OFFSET(0)
stmia r2, {r0-r12}
str r13, [r0,#REG_OFFSET(13)]
str r14, [r0,#REG_OFFSET(15)]
/* load new registers from the second ucontext structure */
add r14, r1, #REG_OFFSET(0)
ldmia r14, {r0-r12}
ldr r13, [r14, #52]
add r14, r14, #56
ldmia r14, {r14, pc}
END(libucontext_swapcontext)