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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2012 by Amaury Pouly
*
* 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.
*
****************************************************************************/
#include "config.h"
.syntax unified
.data
was_aborted:
.word 0
.section .text.safe_read8
.type safe_read8, %function
.global safe_read8
@ bool safe_read8(uint8_t *addr, uint8_t *value)
safe_read8:
@ was_aborted = 0
ldr r2, =was_aborted
mov r3, #0
str r3, [r2]
@ r0=*addr
safe_read8_faulty_addr:
ldrb r0, [r0]
@ if(was_aborted)
ldr r2, [r2]
cmp r2, #1
@ return false;
moveq r0, #0
bxeq lr
@ if(value != NULL)
cmp r1, #0
@ *value = r0
strbne r0, [r1]
@ return true;
mov r0, #1
bx lr
.size safe_read8, . - safe_read8
.section .text.safe_read16
.type safe_read16, %function
.global safe_read16
@ bool safe_read16(uint16_t *addr, uint16_t *value)
safe_read16:
@ was_aborted = 0
ldr r2, =was_aborted
mov r3, #0
str r3, [r2]
@ r0=*addr
safe_read16_faulty_addr:
ldrh r0, [r0]
@ if(was_aborted)
ldr r2, [r2]
cmp r2, #1
@ return false;
moveq r0, #0
bxeq lr
@ if(value != NULL)
cmp r1, #0
@ *value = r0
strhne r0, [r1]
@ return true;
mov r0, #1
bx lr
.size safe_read16, . - safe_read16
.section .text.safe_read32
.type safe_read32, %function
.global safe_read32
@ bool safe_read32(uint32_t *addr, uint32_t *value)
safe_read32:
@ was_aborted = 0
ldr r2, =was_aborted
mov r3, #0
str r3, [r2]
@ r0=*addr
safe_read32_faulty_addr:
ldr r0, [r0]
@ if(was_aborted)
ldr r2, [r2]
cmp r2, #1
@ return false;
moveq r0, #0
bxeq lr
@ if(value != NULL)
cmp r1, #0
@ *value = r0
strne r0, [r1]
@ return true;
mov r0, #1
bx lr
.size safe_read32, . - safe_read32
#if (CONFIG_PLATFORM & PLATFORM_NATIVE)
.section .text.data_abort_handler
.type data_abort_handler, %function
.global data_abort_handler
data_abort_handler:
@ store minimal amount of registers
stmfd sp!, {r0-r1}
@ compute faulty address
sub r0, lr, #8
@ compare to safe_read8
ldr r1, =safe_read8_faulty_addr
cmp r0, r1
beq 1f
@ compare to safe_read16
ldr r1, =safe_read16_faulty_addr
cmp r0, r1
beq 1f
@ compare to safe_read32
ldr r1, =safe_read32_faulty_addr
cmp r0, r1
beq 1f
@ otherwise just normally to UIE
mov r1, #2
b UIE
1:
@ set was_aborted
ldr r1, =was_aborted
mov r0, #1
str r0, [r1]
@ restore registers
ldmfd sp!, {r0-r1}
@ restore mode and jump back to the *next* instruction
subs pc, lr, #4
.size data_abort_handler, . - data_abort_handler
#endif
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