m68k: implement getcontext and setcontext

pull/21/head
Ariadne Conill 2020-12-05 23:54:36 -06:00
parent 76f1fd75b8
commit c462af8a3c
2 changed files with 59 additions and 0 deletions

29
arch/m68k/getcontext.S Normal file
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/*
* 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(getcontext, __getcontext)
FUNC(__getcontext)
move.l 4(%sp), %a0 /* load ucontext_t pointer from stack */
movem.l %d2-%d7, REG_OFFSET(REG_D2)(%a0) /* preserve $d2 through $d7 */
movem.l %a2-%a6, REG_OFFSET(REG_A2)(%a0) /* preserve $a2 through $a6 */
lea 4(%sp), %a1 /* load stack pointer into $a1 */
move.l %a1, REG_OFFSET(REG_SP)(%a0) /* store $a1 in ucontext */
move.l (%sp), REG_OFFSET(REG_PC)(%a0) /* store return address in ucontext's PC register */
clr.l %d0 /* return 0 */
rts
END(__getcontext)

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arch/m68k/setcontext.S Normal file
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/*
* 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, __setcontext)
FUNC(__setcontext)
move.l 4(%sp), %a0 /* load ucontext_t pointer from stack */
move.l REG_OFFSET(REG_SP)(%a0), %sp /* load new stack pointer */
movem.l REG_OFFSET(REG_D2)(%a0), %d2-%d7 /* load $d2 through $d7 */
movem.l REG_OFFSET(REG_A2)(%a0), %a2-%a6 /* load $a2 through $a6 */
clr.l %d0 /* clear $d0 */
move.l REG_OFFSET(REG_PC)(%a0), %a1 /* load jump target */
jmp (%a1) /* jump to *$a1 */
END(__setcontext)