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rockbox/firmware/target/arm/crt0.S
Dave Chapman 8383bff582 TAB policing - no code changes 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15000 a1c6a512-1295-4272-9138-f99709370657
2007-10-06 08:38:25 +00:00

527 lines
12 KiB
ArmAsm
Raw Blame History

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
.section .init.text,"ax",%progbits
.global start
start:
b newstart
.space 4*16
/* Arm bootloader and startup code based on startup.s from the iPodLinux loader
*
* Copyright (c) 2003, Daniel Palffy (dpalffy (at) rainstorm.org)
* Copyright (c) 2005, Bernard Leach <leachbj@bouncycastle.org>
*
*/
newstart:
#if CONFIG_CPU == IMX31L
mov r0,#0xD3
msr cpsr, r0
#else
msr cpsr, #0xd3 /* enter supervisor mode, disable IRQ */
#endif
#if !defined(BOOTLOADER) || (CONFIG_CPU == DM320)
#if !defined(DEBUG)
/* Copy exception handler code to address 0 */
ldr r2, =_vectorsstart
ldr r3, =_vectorsend
ldr r4, =_vectorscopy
1:
cmp r3, r2
ldrhi r5, [r4], #4
strhi r5, [r2], #4
bhi 1b
#else
ldr r1, =vectors
ldr r0, =irq_handler
str r0, [r1, #24]
ldr r0, =fiq_handler
str r0, [r1, #28]
#endif
#endif
#if !defined(BOOTLOADER)
#if !defined(STUB)
/* Zero out IBSS */
ldr r2, =_iedata
ldr r3, =_iend
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
/* Copy the IRAM */
ldr r2, =_iramcopy
ldr r3, =_iramstart
ldr r4, =_iramend
1:
cmp r4, r3
ldrhi r5, [r2], #4
strhi r5, [r3], #4
bhi 1b
#endif /* !STUB */
#endif /* !BOOTLOADER */
/* Initialise bss section to zero */
ldr r2, =_edata
ldr r3, =_end
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
/* Set up some stack and munge it with 0xdeadbeef */
ldr sp, =stackend
mov r3, sp
ldr r2, =stackbegin
ldr r4, =0xdeadbeef
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
#ifdef BOOTLOADER
/* Code for ARM bootloader targets other than iPod go here */
#if CONFIG_CPU == S3C2440
/* Proper initialization pulled from 0x5070 */
/* BWSCON
* Reserved 0
* Bank 0:
* Bus width 10 (16 bit)
* Bank 1:
* Buswidth 00 (8 bit)
* Disable wait 0
* Not using UB/LB 0
* Bank 2:
* Buswidth 10 (32 bit)
* Disable wait 0
* Not using UB/LB 0
* Bank 3:
* Buswidth 10 (32 bit)
* Disable wait 0
* Use UB/LB 1
* Bank 4:
* Buswidth 10 (32 bit)
* Disable wait 0
* Use UB/LB 1
* Bank 5:
* Buswidth 00 (8 bit)
* Disable wait 0
* Not using UB/LB 0
* Bank 6:
* Buswidth 10 (32 bit)
* Disable wait 0
* Not using UB/LB 0
* Bank 7:
* Buswidth 00 (8 bit)
* Disable wait 0
* Not using UB/LB 0
*/
ldr r2,=0x01055102
mov r1, #0x48000000
str r2, [r1]
/* BANKCON0
* Pagemode: normal (1 data) 00
* Pagemode access cycle: 2 clocks 00
* Address hold: 2 clocks 10
* Chip selection hold time: 1 clock 10
* Access cycle: 8 clocks 101
* Chip select setup time: 1 clock 01
* Address setup time: 0 clock 00
*/
ldr r2,=0x00000D60
str r2, [r1, #4]
/* BANKCON1
* Pagemode: normal (1 data) 00
* Pagemode access cycle: 2 clocks 00
* Address hold: 0 clocks 00
* Chip selection hold time: 0 clock 00
* Access cycle: 1 clocks 000
* Chip select setup time: 0 clocks 00
* Address setup time: 0 clocks 00
*/
ldr r2,=0x00000000
str r2, [r1, #8]
/* BANKCON2
* Pagemode: normal (1 data) 00
* Pagemode access cycle: 2 clocks 00
* Address hold: 2 clocks 10
* Chip selection hold time: 2 clocks 10
* Access cycle: 14 clocks 111
* Chip select setup time: 4 clocks 11
* Address setup time: 0 clocks 00
*/
ldr r2,=0x00001FA0
str r2, [r1, #0xC]
/* BANKCON3 */
ldr r2,=0x00001D80
str r2, [r1, #0x10]
/* BANKCON4 */
str r2, [r1, #0x14]
/* BANKCON5 */
ldr r2,=0x00000000
str r2, [r1, #0x18]
/* BANKCON6/7
* SCAN: 9 bit 01
* Trcd: 3 clocks 01
* Tcah: 0 clock 00
* Tcoh: 0 clock 00
* Tacc: 1 clock 000
* Tcos: 0 clock 00
* Tacs: 0 clock 00
* MT: Sync DRAM 11
*/
ldr r2,=0x00018005
str r2, [r1, #0x1C]
/* BANKCON7 */
str r2, [r1, #0x20]
/* REFRESH */
ldr r2,=0x00980501
str r2, [r1, #0x24]
/* BANKSIZE
* BK76MAP: 32M/32M 000
* Reserved: 0 0 (was 1)
* SCLK_EN: always 1 (was 0)
* SCKE_EN: disable 0
* Reserved: 0 0
* BURST_EN: enabled 1
*/
ldr r2,=0x00000090
str r2, [r1, #0x28]
/* MRSRB6 */
ldr r2,=0x00000030
str r2, [r1, #0x2C]
/* MRSRB7 */
str r2, [r1, #0x30]
#if 0
/* This next part I am not sure of the purpose */
/* GPACON */
mov r2,#0x01FFFCFF
str r2,=0x56000000
/* GPADAT */
mov r2,#0x01FFFEFF
str r2,=0x56000004
/* MRSRB6 */
mov r2,#0x00000000
str r2,=0x4800002C
/* GPADAT */
ldr r2,=0x01FFFFFF
mov r1, #0x56000000
str r2, [r1, #4]
/* MRSRB6 */
mov r2,#0x00000030
str r2,=0x4800002C
/* GPACON */
mov r2,#0x01FFFFFF
str r2,=0x56000000
/* End of the unknown */
#endif
/* get the high part of our execute address */
ldr r2, =0xffffff00
and r4, pc, r2
/* Copy bootloader to safe area - 0x31000000 */
mov r5, #0x30000000
add r5, r5, #0x1000000
ldr r6, = _dataend
sub r0, r6, r5 /* length of loader */
add r0, r4, r0 /* r0 points to start of loader */
1:
cmp r5, r6
ldrcc r2, [r4], #4
strcc r2, [r5], #4
bcc 1b
ldr pc, =start_loc /* jump to the relocated start_loc: */
start_loc:
bl main
#elif CONFIG_CPU == IMX31L
mov r0, #0
mcr 15, 0, r0, c7, c7, 0 /* invalidate I cache and D cache */
mcr 15, 0, r0, c8, c7, 0 /* invalidate TLBs */
mcr 15, 0, r0, c7, c10, 4 /* Drain the write buffer */
/* Also setup the Peripheral Port Remap register inside the core */
ldr r0, =0x40000015 /* start from AIPS 2GB region */
mcr p15, 0, r0, c15, c2, 4
/*** L2 Cache setup/invalidation/disable ***/
/* Disable L2 cache first */
ldr r0, =L2CC_BASE_ADDR
ldr r2, [r0, #L2_CACHE_CTL_REG]
bic r2, r2, #0x1
str r2, [r0, #L2_CACHE_CTL_REG]
/*
* Configure L2 Cache:
* - 128k size(16k way)
* - 8-way associativity
* - 0 ws TAG/VALID/DIRTY
* - 4 ws DATA R/W
*/
ldr r1, [r0, #L2_CACHE_AUX_CTL_REG]
and r1, r1, #0xFE000000
ldr r2, =0x00030024
orr r1, r1, r2
str r1, [r0, #L2_CACHE_AUX_CTL_REG]
/* Invalidate L2 */
ldr r1, =0x000000FF
str r1, [r0, #L2_CACHE_INV_WAY_REG]
L2_loop:
/* Poll Invalidate By Way register */
ldr r2, [r0, #L2_CACHE_INV_WAY_REG]
cmp r2, #0
bne L2_loop
/*** End of L2 operations ***/
/* Set up stack for IRQ mode */
mov r0,#0xd2
msr cpsr, r0
ldr sp, =irq_stack
/* Set up stack for FIQ mode */
mov r0,#0xd1
msr cpsr, r0
ldr sp, =fiq_stack
/* Let abort and undefined modes use IRQ stack */
mov r0,#0xd7
msr cpsr, r0
ldr sp, =irq_stack
mov r0,#0xdb
msr cpsr, r0
ldr sp, =irq_stack
/* Switch to supervisor mode */
mov r0,#0xd3
msr cpsr, r0
ldr sp, =stackend
/*remap memory as well as exception vectors*/
/*for now this will be done in bootloader, especially
if usb will be needed within the bootloader to load the
main firmware file. Interrupts will be needed for this
(whether they be swi or irq)*/
bl memory_init
mov r0,#0
ldr r1,=_vectorstart
mov r2,#0
lp: ldr r3,[r1]
add r1,r1,#4
str r3,[r0]
add r0,r0,#4
add r2,r2,#1
cmp r2,#16
bne lp
bl main
.section .vectors,"aw"
_vectorstart:
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
/* Exception vectors */
.global vectors
vectors:
.word start
.word undef_instr_handler
.word software_int_handler
.word prefetch_abort_handler
.word data_abort_handler
.word reserved_handler
.word irqz
.word fiqz
.text
.global irq
.global fiq
.global UIE
undef_instr_handler:
mov r0, lr
mov r1, #0
b UIE
software_int_handler:
reserved_handler:
bl irq_handler
movs pc, lr
prefetch_abort_handler:
sub r0, lr, #4
mov r1, #1
b UIE
data_abort_handler:
sub r0, lr, #8
mov r1, #2
b UIE
/*not working....if we get here, let someone
know....*/
irqz: bl irq_handler
fiqz: bl fiq_handler
UIE:
b UIE
/* 256 words of IRQ stack */
.space 256*4
irq_stack:
/* 256 words of FIQ stack */
.space 256*4
fiq_stack:
#endif
#else /* BOOTLOADER */
/* Set up stack for IRQ mode */
msr cpsr_c, #0xd2
ldr sp, =irq_stack
/* Set up stack for FIQ mode */
msr cpsr_c, #0xd1
ldr sp, =fiq_stack
/* Let abort and undefined modes use IRQ stack */
msr cpsr_c, #0xd7
ldr sp, =irq_stack
msr cpsr_c, #0xdb
ldr sp, =irq_stack
/* Switch to supervisor mode */
msr cpsr_c, #0xd3
ldr sp, =stackend
bl main
/* main() should never return */
/* Exception handlers. Will be copied to address 0 after memory remapping */
#if CONFIG_CPU == IMX31L
_vectorstart:
#endif
.section .vectors,"aw"
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
ldr pc, [pc, #24]
/* Exception vectors */
.global vectors
vectors:
.word start
.word undef_instr_handler
.word software_int_handler
.word prefetch_abort_handler
.word data_abort_handler
.word reserved_handler
.word irq_handler
.word fiq_handler
.text
#ifndef STUB
.global irq
.global fiq
.global UIE
#endif
/* 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:
mov r0, lr
mov r1, #0
b UIE
/* We run supervisor mode most of the time, and should never see a software
exception being thrown. Perhaps make it illegal and call UIE?
*/
software_int_handler:
reserved_handler:
movs pc, lr
prefetch_abort_handler:
sub r0, lr, #4
mov r1, #1
b UIE
data_abort_handler:
sub r0, lr, #8
mov r1, #2
b UIE
#ifdef STUB
UIE:
b UIE
#endif
/* 256 words of IRQ stack */
.space 256*4
irq_stack:
/* 256 words of FIQ stack */
.space 256*4
fiq_stack:
#endif /* BOOTLOADER */
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