u-boot/arch/arm/cpu/s3c44b0/start.S
Wolfgang Denk e03f316974 Drop support for CONFIG_SKIP_RELOCATE_UBOOT
For ARM systems, before ELF relocation was introduced,
CONFIG_SKIP_RELOCATE_UBOOT coul be used to prevent *COPYING* the
U-Boot image from whereever it was loaded to it's link address
(CONFIG_SYS_TEXT_BASE).  The name was badly chosen, as no relocation
was performed at all, it was just a memcpy().

With ELF relocation, this does not work like that any more, and
related boards need to be fixed anyway.  So don't keep this relict any
longer.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Tested-by: Heiko Schocher <hs@denx.de>
Tested-by: Reinhard Meyer <u-boot@emk-elektronik.de>
2010-10-29 21:40:08 +02:00

359 lines
7 KiB
ArmAsm

/*
* Startup Code for S3C44B0 CPU-core
*
* (C) Copyright 2004
* DAVE Srl
*
* http://www.dave-tech.it
* http://www.wawnet.biz
* mailto:info@wawnet.biz
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <asm-offsets.h>
#include <config.h>
#include <version.h>
/*
* Jump vector table
*/
.globl _start
_start: b reset
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
add pc, pc, #0x0c000000
.balignl 16,0xdeadbeef
/*
*************************************************************************
*
* Startup Code (reset vector)
*
* do important init only if we don't start from memory!
* relocate u-boot to ram
* setup stack
* jump to second stage
*
*************************************************************************
*/
.globl _TEXT_BASE
_TEXT_BASE:
.word CONFIG_SYS_TEXT_BASE
/*
* These are defined in the board-specific linker script.
*/
.globl _bss_start
_bss_start:
.word __bss_start
.globl _bss_end
_bss_end:
.word _end
#ifdef CONFIG_USE_IRQ
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
.word 0x0badc0de
/* IRQ stack memory (calculated at run-time) */
.globl FIQ_STACK_START
FIQ_STACK_START:
.word 0x0badc0de
#endif
/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
.word 0x0badc0de
.globl _datarel_start
_datarel_start:
.word __datarel_start
.globl _datarelrolocal_start
_datarelrolocal_start:
.word __datarelrolocal_start
.globl _datarellocal_start
_datarellocal_start:
.word __datarellocal_start
.globl _datarelro_start
_datarelro_start:
.word __datarelro_start
.globl _got_start
_got_start:
.word __got_start
.globl _got_end
_got_end:
.word __got_end
/*
* the actual reset code
*/
reset:
/*
* set the cpu to SVC32 mode
*/
mrs r0,cpsr
bic r0,r0,#0x1f
orr r0,r0,#0xd3
msr cpsr,r0
/*
* we do sys-critical inits only at reboot,
* not when booting from ram!
*/
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
bl cpu_init_crit
/*
* before relocating, we have to setup RAM timing
* because memory timing is board-dependend, you will
* find a lowlevel_init.S in your board directory.
*/
bl lowlevel_init
#endif
/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
ldr r0,=0x00000000
bl board_init_f
/*------------------------------------------------------------------------------*/
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
*/
.globl relocate_code
relocate_code:
mov r4, r0 /* save addr_sp */
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */
mov r7, r2 /* save addr of destination */
/* Set up the stack */
stack_setup:
mov sp, r4
adr r0, _start
ldr r2, _TEXT_BASE
ldr r3, _bss_start
sub r2, r3, r2 /* r2 <- size of armboot */
add r2, r0, r2 /* r2 <- source end address */
cmp r0, r6
beq clear_bss
copy_loop:
ldmia r0!, {r9-r10} /* copy from source address [r0] */
stmia r6!, {r9-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end address [r2] */
blo copy_loop
#ifndef CONFIG_PRELOADER
/* fix got entries */
ldr r1, _TEXT_BASE /* Text base */
mov r0, r7 /* reloc addr */
ldr r2, _got_start /* addr in Flash */
ldr r3, _got_end /* addr in Flash */
sub r3, r3, r1
add r3, r3, r0
sub r2, r2, r1
add r2, r2, r0
fixloop:
ldr r4, [r2]
sub r4, r4, r1
add r4, r4, r0
str r4, [r2]
add r2, r2, #4
cmp r2, r3
blo fixloop
#endif
/*
now copy to sram the interrupt vector
*/
adr r0, real_vectors
add r2, r0, #1024
ldr r1, =0x0c000000
add r1, r1, #0x08
vector_copy_loop:
ldmia r0!, {r3-r10}
stmia r1!, {r3-r10}
cmp r0, r2
blo vector_copy_loop
clear_bss:
#ifndef CONFIG_PRELOADER
ldr r0, _bss_start
ldr r1, _bss_end
ldr r3, _TEXT_BASE /* Text base */
mov r4, r7 /* reloc addr */
sub r0, r0, r3
add r0, r0, r4
sub r1, r1, r3
add r1, r1, r4
mov r2, #0x00000000 /* clear */
clbss_l:str r2, [r0] /* clear loop... */
add r0, r0, #4
cmp r0, r1
bne clbss_l
bl coloured_LED_init
bl red_LED_on
#endif
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
ldr r0, _TEXT_BASE
ldr r2, _board_init_r
sub r2, r2, r0
add r2, r2, r7 /* position from board_init_r in RAM */
/* setup parameters for board_init_r */
mov r0, r5 /* gd_t */
mov r1, r7 /* dest_addr */
/* jump to it ... */
mov lr, r2
mov pc, lr
_board_init_r: .word board_init_r
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
#define INTCON (0x01c00000+0x200000)
#define INTMSK (0x01c00000+0x20000c)
#define LOCKTIME (0x01c00000+0x18000c)
#define PLLCON (0x01c00000+0x180000)
#define CLKCON (0x01c00000+0x180004)
#define WTCON (0x01c00000+0x130000)
cpu_init_crit:
/* disable watch dog */
ldr r0, =WTCON
ldr r1, =0x0
str r1, [r0]
/*
* mask all IRQs by clearing all bits in the INTMRs
*/
ldr r1,=INTMSK
ldr r0, =0x03fffeff
str r0, [r1]
ldr r1, =INTCON
ldr r0, =0x05
str r0, [r1]
/* Set Clock Control Register */
ldr r1, =LOCKTIME
ldrb r0, =800
strb r0, [r1]
ldr r1, =PLLCON
#if CONFIG_S3C44B0_CLOCK_SPEED==66
ldr r0, =0x34031 /* 66MHz (Quartz=11MHz) */
#elif CONFIG_S3C44B0_CLOCK_SPEED==75
ldr r0, =0x610c1 /*B2: Xtal=20mhz Fclk=75MHz */
#else
# error CONFIG_S3C44B0_CLOCK_SPEED undefined
#endif
str r0, [r1]
ldr r1,=CLKCON
ldr r0, =0x7ff8
str r0, [r1]
mov pc, lr
/*************************************************/
/* interrupt vectors */
/*************************************************/
real_vectors:
b reset
b undefined_instruction
b software_interrupt
b prefetch_abort
b data_abort
b not_used
b irq
b fiq
/*************************************************/
undefined_instruction:
mov r6, #3
b reset
software_interrupt:
mov r6, #4
b reset
prefetch_abort:
mov r6, #5
b reset
data_abort:
mov r6, #6
b reset
not_used:
/* we *should* never reach this */
mov r6, #7
b reset
irq:
mov r6, #8
b reset
fiq:
mov r6, #9
b reset