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/*
* Startup code for use with the u-boot bootloader.
*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <asm/setup.h>
#include <asm/thread_info.h>
#include <asm/sysreg.h>
/*
* The kernel is loaded where we want it to be and all caches
* have just been flushed. We get two parameters from u-boot:
*
* r12 contains a magic number (ATAG_MAGIC)
* r11 points to a tag table providing information about
* the system.
*/
.section .init.text,"ax"
.global _start
_start:
/* Initialize .bss */
lddpc r2, bss_start_addr
lddpc r3, end_addr
mov r0, 0
mov r1, 0
1: st.d r2++, r0
cp r2, r3
brlo 1b
/* Initialize status register */
lddpc r0, init_sr
mtsr SYSREG_SR, r0
/* Set initial stack pointer */
lddpc sp, stack_addr
sub sp, -THREAD_SIZE
#ifdef CONFIG_FRAME_POINTER
/* Mark last stack frame */
mov lr, 0
mov r7, 0
#endif
/* Check if the boot loader actually provided a tag table */
lddpc r0, magic_number
cp.w r12, r0
brne no_tag_table
/*
* Save the tag table address for later use. This must be done
* _after_ .bss has been initialized...
*/
lddpc r0, tag_table_addr
st.w r0[0], r11
/* Jump to loader-independent setup code */
rjmp kernel_entry
.align 2
magic_number:
.long ATAG_MAGIC
tag_table_addr:
.long bootloader_tags
bss_start_addr:
.long __bss_start
end_addr:
.long _end
init_sr:
.long 0x007f0000 /* Supervisor mode, everything masked */
stack_addr:
.long init_thread_union
panic_addr:
.long panic
no_tag_table:
sub r12, pc, (. - 2f)
/* branch to panic() which can be far away with that construct */
lddpc pc, panic_addr
2: .asciz "Boot loader didn't provide correct magic number\n"
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