libucontext/arch/sh/setcontext.S

61 lines
1.7 KiB
ArmAsm

/*
* Copyright (c) 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(setcontext, libucontext_setcontext)
ALIAS(__setcontext, libucontext_setcontext)
FUNC(libucontext_setcontext)
mov r4, r0
add #(REG_OFFSET(5)), r0 /* restore GPRs r5-15 */
mov.l @r0+, r5
mov.l @r0+, r6
mov.l @r0+, r7
mov.l @r0+, r8
mov.l @r0+, r9
mov.l @r0+, r10
mov.l @r0+, r11
mov.l @r0+, r12
mov.l @r0+, r13
mov.l @r0+, r14
mov.l @r0+, r15
mov.l @r0+, r2 /* restore PR */
lds.l @r0+, pr
mov.l @r0+, r1 /* restore T-flag */
shlr r1
add #REG_SZ, r0 /* skip GBR (used for TLS) */
lds.l @r0+, mach /* load mach/macl registers */
lds.l @r0+, macl
mov r4, r0 /* bring r0 back to the top of the context */
add #(REG_OFFSET(0)), r1 /* restore r0 into r1 (temporarily) */
mov.l r1, @-r15 /* push to stack from r1 */
mov.l r2, @-r15 /* push PC to stack */
mov.l @(REG_OFFSET(1), r0), r1 /* restore real r1 */
mov.l @(REG_OFFSET(2), r0), r2 /* restore real r2 */
mov.l @(REG_OFFSET(3), r0), r3 /* restore real r2 */
mov.l @(REG_OFFSET(4), r0), r4 /* restore real r2 */
mov.l @r15+, r0 /* pop PC from stack */
jmp @r0 /* jump to new PC */
mov.l @r15+, r0 /* pop original r0 from stack */
END(libucontext_setcontext)