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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id: crt0.S 18776 2008-10-11 18:32:17Z gevaerts $
*
* Copyright (C) 2008 by Marcoen Hirschberg
* Copyright (C) 2008 by Denes Balatoni
*
* 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.
*
****************************************************************************/
#define ASM
#include "config.h"
#include "cpu.h"
#define CACHE_NONE 0
#define CACHE_ALL 0x0C
.section .intvect,"ax",%progbits
.global start
.global _newstart
/* Exception vectors */
start:
b _newstart
ldr pc, =undef_instr_handler
ldr pc, =software_int_handler
ldr pc, =prefetch_abort_handler
ldr pc, =data_abort_handler
ldr pc, =reserved_handler
ldr pc, =irq_handler
ldr pc, =fiq_handler
.ltorg
_newstart:
#if !defined(BOOTLOADER)
ldr pc, =newstart2 // we do not want to execute from 0x0 as iram will be mapped there
.section .init.text,"ax",%progbits
newstart2:
#endif
msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
#ifdef BOOTLOADER
/* Relocate ourself to IRAM - we have been loaded to DRAM */
mov r0, #0x08000000 /* source (DRAM) */
mov r1, #0x22000000 /* dest (IRAM) */
ldr r2, =_dataend
1:
cmp r2, r1
ldrhi r3, [r0], #4
strhi r3, [r1], #4
bhi 1b
ldr pc, =start_loc /* jump to the relocated start_loc: */
start_loc:
#endif
mrc 15, 0, r0, c1, c0, 0
bic r0, r0, #0x1000
bic r0, r0, #0x5
mcr 15, 0, r0, c1, c0, 0 // disable caches and protection unit
.cleancache:
mrc p15, 0, r15,c7,c10,3
bne .cleancache
mov r0, #0
mcr p15, 0, r0,c7,c10,4
mcr p15, 0, r0,c7,c5,0
bl ttb_init
mov r0, #0 @ physical address
mov r1, #0 @ virtual address
mov r2, #0x380 @ size (all memory)
mov r3, #CACHE_ALL
bl map_section
mov r0, #0x38000000 @ physical address
mov r1, #0x38000000 @ virtual address
mov r2, #0x80 @ size (AHB/APB)
mov r3, #CACHE_NONE
bl map_section
bl enable_mmu
mrc 15, 0, r0, c1, c0, 0
orr r0, r0, #0x5
orr r0, r0, #0x1000
mcr 15, 0, r0, c1, c0, 0 // re-enable protection unit and caches
ldr r1, =0x38e00000
add r2, r1, #0x00001000
add r3, r1, #0x00002000
sub r4, r0, #1
str r4, [r1,#0x14]
str r4, [r2,#0x14]
str r4, [r1,#0xf00]
str r4, [r2,#0xf00]
str r4, [r3,#0x08]
str r4, [r3,#0x0c]
str r0, [r1,#0x14]
str r0, [r2,#0x14]
#if !defined(BOOTLOADER)
/* Copy interrupt vectors to iram */
ldr r2, =_intvectstart
ldr r3, =_intvectend
ldr r4, =_intvectcopy
1:
cmp r3, r2
ldrhi r1, [r4], #4
strhi r1, [r2], #4
bhi 1b
#endif
/* Initialise bss section to zero */
ldr r2, =_edata
ldr r3, =_end
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
#ifndef BOOTLOADER
/* Copy icode and data to ram */
ldr r2, =_iramstart
ldr r3, =_iramend
ldr r4, =_iramcopy
1:
cmp r3, r2
ldrhi r1, [r4], #4
strhi r1, [r2], #4
bhi 1b
/* Initialise ibss section to zero */
ldr r2, =_iedata
ldr r3, =_iend
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
#endif
/* Set up stack for IRQ mode */
msr cpsr_c, #0xd2
ldr sp, =_irqstackend
/* Set up stack for FIQ mode */
msr cpsr_c, #0xd1
ldr sp, =_fiqstackend
/* Let svc, abort and undefined modes use irq stack */
msr cpsr_c, #0xd3
ldr sp, =_irqstackend
msr cpsr_c, #0xd7
ldr sp, =_irqstackend
msr cpsr_c, #0xdb
ldr sp, =_irqstackend
/* Switch to sys mode */
msr cpsr_c, #0xdf
/* Set up some stack and munge it with 0xdeadbeef */
ldr sp, =stackend
ldr r2, =stackbegin
ldr r3, =0xdeadbeef
1:
cmp sp, r2
strhi r3, [r2], #4
bhi 1b
bl main
.text
/* .global UIE*/
/* All illegal exceptions call into UIE with exception address as first
* parameter. This is calculated differently depending on which exception
* we're in. Second parameter is exception number, used for a string lookup
* in UIE. */
undef_instr_handler:
sub r0, lr, #4
mov r1, #0
b UIE
/* We run sys mode most of the time, and should never see a software
* exception being thrown. Make it illegal and call UIE. */
software_int_handler:
reserved_handler:
sub r0, lr, #4
mov r1, #4
b UIE
prefetch_abort_handler:
sub r0, lr, #4
mov r1, #1
b UIE
data_abort_handler:
sub r0, lr, #8
mov r1, #2
b UIE
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