blob: cf37647e27517bf4f1965da28775cad833affd76 [file] [log] [blame]
/*
* This file is part of the coreboot 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; version 2 of
* the License.
*
* 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.
*
* Early initialization code for ARM architecture.
*
* This file is based off of the OMAP3530/ARM Cortex start.S file from Das
* U-Boot, which itself got the file from armboot.
*/
#include <arch/asm.h>
ENTRY(_start)
/*
* Set the CPU to System mode with IRQ and FIQ disabled. Prefetch/Data
* aborts may happen early and crash before the abort handlers are
* installed, but at least the problem will show up near the code that
* causes it.
*/
msr cpsr_cxf, #0xdf
/*
* Initialize the stack to a known value. This is used to check for
* stack overflow later in the boot process.
*/
ldr r0, =_stack
ldr r1, =_estack
ldr r2, =0xdeadbeef
init_stack_loop:
str r2, [r0]
add r0, #4
cmp r0, r1
bne init_stack_loop
/* Set stackpointer in internal RAM to call bootblock main() */
call_bootblock:
ldr sp, =_estack /* Set up stack pointer */
ldr r0,=0x00000000
/*
* The current design of cpu_info places the
* struct at the top of the stack. The number of
* words pushed must be at least as large as that
* struct.
*/
push {r0-r2}
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
/*
* Use "bl" instead of "b" even though we do not intend to return.
* "bl" gets compiled to "blx" if we're transitioning from ARM to
* Thumb. However, "b" will not and GCC may attempt to create a
* wrapper which is currently broken.
*/
bl main
ENDPROC(_start)