libucontext/arch/mips/swapcontext.S

83 lines
2.0 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.
*/
LOCALSZ = 2
#include "defs.h"
A1_OFFSET = FRAMESZ - (1 * REG_SZ)
ALIAS(swapcontext, libucontext_swapcontext)
ALIAS(__swapcontext, libucontext_swapcontext)
FUNC(libucontext_swapcontext)
/* copy $gp, $sp, $fp to temporary registers so we don't clobber them */
move $a2, $gp
move $a3, $sp
PUSH_FRAME(libucontext_swapcontext)
/* set registers */
sd $s0, REG_OFFSET(16)($a0)
sd $s1, REG_OFFSET(17)($a0)
sd $s2, REG_OFFSET(18)($a0)
sd $s3, REG_OFFSET(19)($a0)
sd $s4, REG_OFFSET(20)($a0)
sd $s5, REG_OFFSET(21)($a0)
sd $s6, REG_OFFSET(22)($a0)
sd $s7, REG_OFFSET(23)($a0)
sd $a2, REG_OFFSET(28)($a0)
sd $a3, REG_OFFSET(29)($a0)
sd $fp, REG_OFFSET(30)($a0)
sd $ra, REG_OFFSET(31)($a0)
sd $ra, (MCONTEXT_PC)($a0)
/* copy new context address in $a1 to stack */
sd $a1, A1_OFFSET($sp)
/* load new context address into $v0 */
ld $v0, A1_OFFSET($sp)
/* load the registers */
ld $a0, REG_OFFSET(4)($v0)
ld $a1, REG_OFFSET(5)($v0)
ld $a2, REG_OFFSET(6)($v0)
ld $a3, REG_OFFSET(7)($v0)
ld $s0, REG_OFFSET(16)($v0)
ld $s1, REG_OFFSET(17)($v0)
ld $s2, REG_OFFSET(18)($v0)
ld $s3, REG_OFFSET(19)($v0)
ld $s4, REG_OFFSET(20)($v0)
ld $s5, REG_OFFSET(21)($v0)
ld $s6, REG_OFFSET(22)($v0)
ld $s7, REG_OFFSET(23)($v0)
ld $gp, REG_OFFSET(28)($v0)
ld $sp, REG_OFFSET(29)($v0)
ld $fp, REG_OFFSET(30)($v0)
ld $ra, REG_OFFSET(31)($v0)
ld $t9, (MCONTEXT_PC)($v0)
move $v0, $zero
jr $t9
fail:
la $t9, exit
POP_FRAME(libucontext_swapcontext)
move $v0, $zero
jalr $t9
END(libucontext_swapcontext)