104 lines
2.9 KiB
ArmAsm
104 lines
2.9 KiB
ArmAsm
/*
|
|
* Early initialization code for ARMv7 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.
|
|
*
|
|
* Copyright (c) 2004 Texas Instruments <r-woodruff2@ti.com>
|
|
* Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
|
|
* Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
|
|
* Copyright (c) 2002 Gary Jennejohn <garyj@denx.de>
|
|
* Copyright (c) 2003 Richard Woodruff <r-woodruff2@ti.com>
|
|
* Copyright (c) 2003 Kshitij <kshitij@ti.com>
|
|
* Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
|
|
* Copyright (c) 2013 The Chromium OS Authors
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <arch/asm.h>
|
|
|
|
.arm
|
|
/*
|
|
* Just in case the maskrom or the vendor basic firmware passes on a
|
|
* parameter when calling the bootblock, store it here for handling by C
|
|
* code.
|
|
*/
|
|
.section .bss, "aw" @nobits
|
|
.global maskrom_param
|
|
maskrom_param:
|
|
.word 0
|
|
|
|
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
|
|
bl _thumb_start
|
|
ENDPROC(_start)
|
|
|
|
.thumb
|
|
ENTRY(_thumb_start)
|
|
|
|
/* Preserve the maskrom passed value, if any */
|
|
mov r10, r0
|
|
|
|
bl arm_init_caches
|
|
|
|
/*
|
|
* From Cortex-A Series Programmer's Guide:
|
|
* Only CPU 0 performs initialization. Other CPUs go into WFI
|
|
* to do this, first work out which CPU this is
|
|
* this code typically is run before any other initialization step
|
|
*/
|
|
mrc p15, 0, r1, c0, c0, 5 @ Read Multiprocessor Affinity Register
|
|
and r1, r1, #0x3 @ Extract CPU ID bits
|
|
cmp r1, #0
|
|
bne wait_for_interrupt @ If this is not core0, wait
|
|
|
|
/*
|
|
* 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
|
|
|
|
call_bootblock:
|
|
|
|
/* Restore parameter passed in by maskrom/vendor firmware. */
|
|
ldr r0, =maskrom_param
|
|
str r10, [r0]
|
|
|
|
/* Set stackpointer in internal RAM to call bootblock main() */
|
|
ldr sp, =_estack
|
|
ldr r0,=0x00000000
|
|
/*
|
|
* The current design of cpu_info places the struct at the top of the
|
|
* stack. Free enough space to accomodate for that, but make sure it's
|
|
* 8-byte aligned for ABI compliance.
|
|
*/
|
|
sub sp, sp, #16
|
|
bl main
|
|
|
|
wait_for_interrupt:
|
|
wfi
|
|
mov pc, lr @ back to my caller
|
|
ENDPROC(_thumb_start)
|