You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
65 lines
1.3 KiB
ArmAsm
65 lines
1.3 KiB
ArmAsm
/* See the end of this file for copyright, license, and warranty information. */
|
|
|
|
.include "asm.S"
|
|
|
|
.text
|
|
|
|
/* int arch_enter(void *sp); */
|
|
.extern arch_enter
|
|
|
|
/* void *sched_switch(void *sp); */
|
|
.extern sched_switch
|
|
|
|
/* void handle_svc(void); */
|
|
func_begin handle_svc
|
|
/*
|
|
* Syscalls on Cortex-M use the following parameter calling convention:
|
|
*
|
|
* number: r7
|
|
* rval: r0
|
|
* arg1: r0
|
|
* arg2: r1
|
|
* arg3: r2
|
|
* arg4: r3
|
|
* arg5: r4
|
|
* arg6: r5
|
|
*/
|
|
|
|
/*
|
|
* like in irq_pend_sv, we save everything on the stack to make early
|
|
* process switching possible in case the syscall is blocking.
|
|
*/
|
|
push {r4-r11,lr}
|
|
|
|
mov r0, sp
|
|
bl arch_enter /* int need_resched = arch_enter(sp); */
|
|
|
|
cmp r0, #0
|
|
beq svc_out
|
|
|
|
mov r0, sp
|
|
bl sched_switch /* sp = sched_switch(sp); */
|
|
mov sp, r0
|
|
|
|
clrex
|
|
|
|
svc_out:
|
|
pop {r4-r11,lr}
|
|
|
|
bx lr
|
|
|
|
func_end handle_svc
|
|
|
|
/*
|
|
* This file is part of Ardix.
|
|
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
|
|
*
|
|
* Ardix is non-violent software: you may only use, redistribute,
|
|
* and/or modify it under the terms of the CNPLv6+ as found in
|
|
* the LICENSE file in the source code root directory or at
|
|
* <https://git.pixie.town/thufie/CNPL>.
|
|
*
|
|
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
|
|
* permitted by applicable law. See the CNPLv6+ for details.
|
|
*/
|