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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.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
.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
#if CONFIG_CPU==S5L8700
.word 0x43554644 /* DFUC */
#endif
.ltorg
_newstart:
ldr pc, =newstart2 // we do not want to execute from 0x0 as iram will be mapped there
.section .init.text,"ax",%progbits
newstart2:
msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
#ifdef ROCKBOX_BIG_ENDIAN
mov r1, #0x80
mrc 15, 0, r0, c1, c0, 0
orr r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // set bigendian
#endif
ldr r1, =0x3c800000 // disable watchdog
mov r0, #0xa5
str r0, [r1]
mov r0, #0
ldr r1, =0x39c00008
str r0, [r1] // mask all interrupts
ldr r1, =0x39c00020
str r0, [r1] // mask all external interrupts
mvn r0, #0
mov r1, #0x39c00000
str r0, [r1] // irq priority
ldr r1, =0x39c00010
str r0, [r1] // clear pending interrupts
ldr r1, =0x39c0001c
str r0, [r1] // clear pending external interrupts
// ldr r1, =0x3cf00000
// ldr r0, [r1]
// mvn r2, #0x30
// and r0, r0, r2
// mov r2, #0x10
// orr r0, r0, r2
// str r0, [r1]
// ldr r1, =0x3cf00004
// ldr r0, [r1]
// mov r2, #4
// orr r0, r0, r2
// str r0, [r1] // switch backlight on
ldr r1, =0x3c500000 // CLKCON
ldr r0, =0x00800080
str r0, [r1]
ldr r1, =0x3c500024 // PLLCON
mov r0, #0
str r0, [r1]
ldr r1, =0x3c500004 // PLL0PMS
#ifdef IPOD_NANO2G
ldr r0, =0x21200
#else
ldr r0, =0x1ad200
#endif
str r0, [r1]
ldr r1, =0x3c500014 // PLL0LCNT
ldr r0, =8100
str r0, [r1]
ldr r1, =0x3c500024 // PLLCON
mov r0, #1
str r0, [r1]
ldr r1, =0x3c500020 // PLLLOCK
1:
ldr r0, [r1]
tst r0, #1
beq 1b
ldr r1, =0x3c50003c // CLKCON2
mov r0, #0x80
str r0, [r1]
ldr r1, =0x3c500000 // CLKCON
ldr r0, =0x20803180
str r0, [r1] // FCLK_CPU = 200MHz, HCLK = 100MHz, PCLK = 50MHz, other clocks off
ldr r2, =0xc0000078
mrc 15, 0, r0, c1, c0, 0
mvn r1, #0xc0000000
and r0, r0, r1
orr r0, r0, r2
mcr 15, 0, r0, c1, c0, 0 // asynchronous clocking mode
nop
nop
nop
nop
// ldr r0, =0x10100000
// ldr r1, =0x38200034
// str r0, [r1] // SRAM0/1 data width 16 bit
// ldr r0, =0x00220922
// ldr r7, =0x38200038
// str r0, [r7] // SRAM0/1 clocks
// ldr r0, =0x00220922
// ldr r9, =0x3820003c
// str r0, [r9] // SRAM2/3 clocks
// nop
// nop
// nop
// nop
ldr r1, =0x3c500000
mov r0, #0 // 0x0
str r0, [r1, #40] // enable clock for all peripherals
mov r0, #0 // 0x0
str r0, [r1, #44] // do not enter any power saving mode
mov r1, #0x1
mrc 15, 0, r0, c1, c0, 0
bic r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // disable protection unit
mov r1, #0x4
mrc 15, 0, r0, c1, c0, 0
bic r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // dcache disable
mov r1, #0x1000
mrc 15, 0, r0, c1, c0, 0
bic r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // icache disable
mov r1, #0
1:
mov r0, #0
2:
orr r2, r1, r0
mcr 15, 0, r2, c7, c14, 2 // clean and flush dcache single entry
add r0, r0, #0x10
cmp r0, #0x40
bne 2b
add r1, r1, #0x4000000
cmp r1, #0x0
bne 1b
nop
nop
mov r0, #0
mcr 15, 0, r0, c7, c10, 4 // clean and flush whole dcache
mov r0, #0
mcr 15, 0, r0, c7, c5, 0 // flush icache
mov r0, #0
mcr 15, 0, r0, c7, c6, 0 // flush dcache
mov r0, #0x3f
mcr 15, 0, r0, c6, c0, 1
mov r0, #0x2f
mcr 15, 0, r0, c6, c1, 1
ldr r0, =0x0800002f
mcr 15, 0, r0, c6, c2, 1
ldr r0, =0x22000023
mcr 15, 0, r0, c6, c3, 1
ldr r0, =0x24000027
mcr 15, 0, r0, c6, c4, 1
mov r0, #0x3f
mcr 15, 0, r0, c6, c0, 0
mov r0, #0x2f
mcr 15, 0, r0, c6, c1, 0
ldr r0, =0x0800002f
mcr 15, 0, r0, c6, c2, 0
ldr r0, =0x22000023
mcr 15, 0, r0, c6, c3, 0
ldr r0, =0x24000029
mcr 15, 0, r0, c6, c4, 0
mov r0, #0x1e
mcr 15, 0, r0, c2, c0, 1
mov r0, #0x1e
mcr 15, 0, r0, c2, c0, 0
mov r0, #0x1e
mcr 15, 0, r0, c3, c0, 0
ldr r0, =0x0000ffff
mcr 15, 0, r0, c5, c0, 1
ldr r0, =0x0000ffff
mcr 15, 0, r0, c5, c0, 0 // set up protection and caching
mov r1, #0x4
mrc 15, 0, r0, c1, c0, 0
orr r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // dcache enable
mov r1, #0x1000
mrc 15, 0, r0, c1, c0, 0
orr r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // icache enable
mov r1, #0x1
mrc 15, 0, r0, c1, c0, 0
orr r0, r0, r1
mcr 15, 0, r0, c1, c0, 0 // enable protection unit
#if CONFIG_CPU==S5L8700
/* 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
#if CONFIG_CPU==S5L8700
/* Copy icode and data to ram */
ldr r2, =_datastart
ldr r3, =_dataend
ldr r4, =_datacopy
1:
cmp r3, r2
ldrhi r1, [r4], #4
strhi r1, [r2], #4
bhi 1b
#endif
/* 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
/* 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 abort and undefined modes use IRQ stack */
msr cpsr_c, #0xd7
ldr sp, =_irqstackend
msr cpsr_c, #0xdb
ldr sp, =_irqstackend
/* Switch back to supervisor mode */
msr cpsr_c, #0xd3
// if we did not switch remap on, device
// would crash when MENU is pressed,
// as that button is connected to BOOT_MODE pin
#if CONFIG_CPU==S5L8700
ldr r1, =0x38200000
ldr r0, [r1]
mvn r2, #0x10000
and r0, r0, r2
mov r2, #0x1
orr r0, r0, r2
str r0, [r1] // remap iram to address 0x0
#endif
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:
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
|
