rockbox/utils/hwstub/stub/asm/arm/atomic_rw.S
Marcin Bukat cd04a5f1aa hwstub/qeditor: add support for atomic read/writes
The current code assumed that READ/WRITE would produce atomic read/writes for
8/16/32-bit words, which in turned put assumption on the memcpy function.
Since some memcpy implementation do not always guarantee such strong assumption,
introduce two new operation READ/WRITE_ATOMIC which provide the necessary
tools to do correct read and write to register in a single memory access.

Change-Id: I37451bd5057bb0dcaf5a800d8aef8791c792a090
2014-11-18 23:30:44 +01:00

58 lines
1.6 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
*
* Copyright (C) 2014 by Marcin Bukat
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
.section .text, "ax", %progbits
.global target_read8
.type target_read8, %function
.global target_read16
.type target_read16, %function
.global target_read32
.type target_read32, %function
.global target_write8
.type target_write8, %function
.global target_write16
.type target_write16, %function
.global target_write32
.type target_write32, %function
target_read8:
ldrb r0, [r0]
bx lr
target_read16:
ldrh r0, [r0]
bx lr
target_read32:
ldr r0, [r0]
bx lr
target_write8:
strb r1, [r0]
bx lr
target_write16:
strh r1, [r0]
bx lr
target_write32:
str r1, [r0]
bx lr