58 lines
1.4 KiB
ArmAsm
58 lines
1.4 KiB
ArmAsm
/* See the end of this file for copyright, license, and warranty information. */
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.include "asm.S"
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/* this is only invoked from user space, obviously */
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.section .text.shared
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.global __syscall_return_point
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/* int syscall(int number, int arg1, int arg2, int arg3, int arg4, int arg5, int arg6); */
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func_begin syscall
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/*
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* arg | syscall | AAPCS
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* -------|---------|---------
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* number | r7 | r0
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* arg1 | r0 | r1
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* arg2 | r1 | r2
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* arg3 | r2 | r3
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* arg4 | r3 | sp + 0
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* arg5 | r4 | sp + 4
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* arg6 | r5 | sp + 8
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*/
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push {r4-r5,r7}
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mov r7, r0 /* number */
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mov r0, r1 /* arg1 */
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mov r1, r2 /* arg2 */
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mov r2, r3 /* arg3 */
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/* stack params begin at 12 bytes offset because we already pushed three registers */
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ldr r3, [sp, #12] /* arg4 */
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ldr r4, [sp, #16] /* arg5 */
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ldr r5, [sp, #20] /* arg6 */
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svc #0
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__syscall_return_point:
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pop {r4-r5,r7}
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/* r0 (return value) is set by the kernel */
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bx lr
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func_end syscall
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/*
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* This file is part of Ardix.
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* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
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*
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* Ardix is non-violent software: you may only use, redistribute,
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* and/or modify it under the terms of the CNPLv6+ as found in
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* the LICENSE file in the source code root directory or at
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* <https://git.pixie.town/thufie/CNPL>.
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*
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* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
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* permitted by applicable law. See the CNPLv6+ for details.
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*/
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