u-boot/arch/arm/cpu/arm926ejs/spear/start.S

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/*
* armboot - Startup Code for ARM926EJS CPU-core
*
* Copyright (c) 2003 Texas Instruments
*
* ----- Adapted for OMAP1610 OMAP730 from ARM925t code ------
*
* 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>
*
* 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 <config.h>
.globl _start
_start:
b reset
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
ldr pc, _data_abort
ldr pc, _not_used
ldr pc, _irq
ldr pc, _fiq
_undefined_instruction:
_software_interrupt:
_prefetch_abort:
_data_abort:
_not_used:
_irq:
_fiq:
.word infinite_loop
infinite_loop:
b infinite_loop
/*
*************************************************************************
*
* Startup Code (reset vector)
*
* Below are the critical initializations already taken place in BootROM.
* So, these are not taken care in Xloader
* 1. Relocation to RAM
* 2. Initializing stacks
*
*************************************************************************
*/
/*
* the actual reset code
*/
reset:
/*
* Xloader has to return back to BootROM in a few cases.
* eg. Ethernet boot, UART boot, USB boot
* Saving registers for returning back
*/
stmdb sp!, {r0-r12,r14}
bl cpu_init_crit
/*
* Clearing bss area is not done in Xloader.
* BSS area lies in the DDR location which is not yet initialized
* bss is assumed to be uninitialized.
*/
bl spl_boot
ldmia sp!, {r0-r12,pc}
/*
*************************************************************************
*
* CPU_init_critical registers
*
* setup important registers
* setup memory timing
*
*************************************************************************
*/
cpu_init_crit:
/*
* flush v4 I/D caches
*/
mov r0, #0
mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */
mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */
/*
* enable instruction cache
*/
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #0x00001000 /* set bit 12 (I) I-Cache */
mcr p15, 0, r0, c1, c0, 0
/*
* Go setup Memory and board specific bits prior to relocation.
*/
stmdb sp!, {lr}
bl lowlevel_init /* go setup pll,mux,memory */
ldmia sp!, {pc}