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.
70 lines
1.5 KiB
ArmAsm
70 lines
1.5 KiB
ArmAsm
/* See the end of this file for copyright, license, and warranty information. */
|
|
|
|
.syntax unified
|
|
.thumb
|
|
.cpu cortex-m3
|
|
|
|
.macro func_begin name
|
|
.global \name
|
|
.type \name, "function"
|
|
\name :
|
|
.endm
|
|
|
|
.macro func_end name
|
|
.size \name, .-\name
|
|
.endm
|
|
|
|
.macro prepare_entry
|
|
/*
|
|
* Hardware automatically saves r0-r3, r12, pc, lr, and psr onto the
|
|
* stack that was used before exception entry. Bit 2 in lr is 1 if the
|
|
* psp was used, and 0 if msp was used. We store the appropriate stack
|
|
* pointer into r12 and push it onto the stack
|
|
*/
|
|
tst lr, #(1 << 2)
|
|
ite ne
|
|
mrsne r12, psp
|
|
moveq r12, sp
|
|
|
|
/*
|
|
* The kernel doesn't like to be interrupted.
|
|
* We don't wanna be impolite and hurt its feelings.
|
|
*/
|
|
cpsid i
|
|
|
|
/*
|
|
* This push matches struct exc_context, r12 is the old stack pointer
|
|
* (which conveniently points to the remaining registers that were
|
|
* saved by hardware, including the original value of r12 before entry).
|
|
*/
|
|
push {r4-r12,lr}
|
|
.endm
|
|
|
|
.macro prepare_leave
|
|
pop {r4-r12,lr}
|
|
|
|
clrex
|
|
|
|
/* Turn interrupts back on */
|
|
cpsie i
|
|
|
|
tst lr, #(1 << 2)
|
|
ite ne
|
|
msrne psp, r12
|
|
moveq sp, r12
|
|
|
|
.endm prepare_leave
|
|
|
|
/*
|
|
* This file is part of Ardix.
|
|
* Copyright (c) 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.
|
|
*/
|