64 lines
1.3 KiB
ArmAsm
64 lines
1.3 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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.text
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/* int arch_enter(void *sp); */
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.extern arch_enter
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/* void *sched_switch(void *sp); */
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.extern sched_switch
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/* void handle_svc(void); */
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func_begin handle_svc
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/*
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* Syscalls on Cortex-M use the following parameter calling convention:
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*
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* number: r7
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* rval: r0
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* arg1: r0
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* arg2: r1
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* arg3: r2
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* arg4: r3
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* arg5: r4
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* arg6: r5
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*/
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/*
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* like in irq_pend_sv, we save everything on the stack to make early
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* process switching possible in case the syscall is blocking.
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*/
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push {r4-r11,lr}
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mov r0, sp
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bl arch_enter /* int need_resched = arch_enter(sp); */
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cmp r0, #0
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beq svc_out
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mov r0, sp
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bl sched_switch /* sp = sched_switch(sp); */
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mov sp, r0
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clrex
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svc_out:
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pop {r4-r11,lr}
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bx lr
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func_end handle_svc
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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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