2020-12-11 22:37:21 +00:00
|
|
|
/*
|
|
|
|
|
* 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(swapcontext, libucontext_swapcontext)
|
2021-01-08 09:30:50 +00:00
|
|
|
ALIAS(__swapcontext, libucontext_swapcontext)
|
2020-12-11 22:37:21 +00:00
|
|
|
|
|
|
|
|
FUNC(libucontext_swapcontext)
|
|
|
|
|
mov r4, r0 /* move r4 to r0, and increment by REG_OFFSET(REG_MACL) + REG_SZ. */
|
|
|
|
|
add #(REG_OFFSET(REG_MACL + 1)), r0
|
|
|
|
|
|
|
|
|
|
sts.l macl, @-r0 /* save macl/mach registers */
|
|
|
|
|
sts.l mach, @-r0
|
|
|
|
|
|
|
|
|
|
stc.l gbr, @-r0 /* save gbr register */
|
|
|
|
|
|
|
|
|
|
movt r1 /* load T-flag into r1 */
|
|
|
|
|
mov.l r1, @-r0 /* save T-flag as SR register */
|
|
|
|
|
|
|
|
|
|
sts.l pr, @-r0 /* save current PR */
|
|
|
|
|
sts.l pr, @-r0 /* save current PR as PC as well */
|
|
|
|
|
|
2020-12-12 05:04:17 +00:00
|
|
|
mov.l r15, @-r0 /* preserve registers backwards, from r15 to r1 */
|
|
|
|
|
mov.l r14, @-r0
|
|
|
|
|
mov.l r13, @-r0
|
|
|
|
|
mov.l r12, @-r0
|
|
|
|
|
mov.l r11, @-r0
|
|
|
|
|
mov.l r10, @-r0
|
|
|
|
|
mov.l r9, @-r0
|
|
|
|
|
mov.l r8, @-r0
|
|
|
|
|
mov.l r7, @-r0
|
|
|
|
|
mov.l r6, @-r0
|
|
|
|
|
mov.l r5, @-r0
|
|
|
|
|
mov.l r4, @-r0
|
|
|
|
|
mov.l r3, @-r0
|
|
|
|
|
mov.l r2, @-r0
|
|
|
|
|
mov.l r1, @-r0
|
|
|
|
|
|
|
|
|
|
mov r0, r1
|
|
|
|
|
mov #0, r0
|
|
|
|
|
|
|
|
|
|
mov.l r0, @-r1 /* preserve r0 as explicit zero */
|
|
|
|
|
|
2020-12-11 22:37:21 +00:00
|
|
|
mov r5, r0 /* now restore the new context */
|
|
|
|
|
|
2020-12-12 05:57:58 +00:00
|
|
|
add #(REG_OFFSET(6)), r0 /* restore GPRs r6-15 */
|
|
|
|
|
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 */
|
2020-12-11 22:37:21 +00:00
|
|
|
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
|
|
|
|
|
|
2020-12-12 05:57:58 +00:00
|
|
|
mov r5, 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 r3 */
|
|
|
|
|
mov.l @(REG_OFFSET(4), r0), r4 /* restore real r4 */
|
|
|
|
|
mov.l @(REG_OFFSET(5), r0), r5 /* restore real r5 */
|
|
|
|
|
|
|
|
|
|
mov.l @r15+, r0 /* pop PC from stack */
|
|
|
|
|
|
|
|
|
|
jmp @r0 /* jump to new PC */
|
|
|
|
|
|
|
|
|
|
mov.l @r15+, r0 /* pop original r0 from stack */
|
2020-12-11 22:37:21 +00:00
|
|
|
END(libucontext_swapcontext)
|
