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/*
* start-arm.c
*
* Copyright (c) 2010 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* 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 version 2
* as published by the Free Software Foundation.
*
* 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 <common.h>
#include <init.h>
#include <asm/barebox-arm.h>
#include <asm/system.h>
#include <asm-generic/memory_layout.h>
void __naked __section(.text_entry) exception_vectors(void)
{
__asm__ __volatile__ (
"b reset\n" /* reset */
"ldr pc, =undefined_instruction\n" /* undefined instruction */
"ldr pc, =software_interrupt\n" /* software interrupt (SWI) */
"ldr pc, =prefetch_abort\n" /* prefetch abort */
"ldr pc, =data_abort\n" /* data abort */
"ldr pc, =not_used\n" /* (reserved) */
"ldr pc, =irq\n" /* irq (interrupt) */
"ldr pc, =fiq\n" /* fiq (fast interrupt) */
);
}
extern char __bss_start, _end;
/*
* The actual reset vector. This code is position independent and usually
* does not run at the address it's linked at.
*/
void __naked __bare_init reset(void)
{
uint32_t r;
/* set the cpu to SVC32 mode */
__asm__ __volatile__("mrs %0, cpsr":"=r"(r));
r &= ~0x1f;
r |= 0xd3;
__asm__ __volatile__("msr cpsr, %0" : : "r"(r));
__asm__ __volatile__ (
"bl __mmu_cache_flush;"
:
:
: "r0", "r1", "r2", "r3", "r6", "r10", "r12", "cc", "memory"
);
/* disable MMU stuff and caches */
r = get_cr();
r &= ~(CR_M | CR_C | CR_B | CR_S | CR_R | CR_V);
r |= CR_A | CR_I;
set_cr(r);
#ifdef CONFIG_MACH_DO_LOWLEVEL_INIT
board_init_lowlevel();
#endif
board_init_lowlevel_return();
}
/*
* Board code can jump here by either returning from board_init_lowlevel
* or by calling this funtion directly.
*/
void __naked __bare_init board_init_lowlevel_return(void)
{
uint32_t r;
/* Setup the stack */
r = STACK_BASE + STACK_SIZE - 16;
__asm__ __volatile__("mov sp, %0" : : "r"(r));
/* Get runtime address of this function */
__asm__ __volatile__("adr %0, 0":"=r"(r));
/* Get start of binary image */
r -= (uint32_t)&board_init_lowlevel_return - TEXT_BASE;
/* relocate to link address if necessary */
if (r != TEXT_BASE)
memcpy((void *)TEXT_BASE, (void *)r,
(unsigned int)&__bss_start - TEXT_BASE);
/* clear bss */
memset(&__bss_start, 0, &_end - &__bss_start);
/* call start_barebox with its absolute address */
r = (unsigned int)&start_barebox;
__asm__ __volatile__("mov pc, %0" : : "r"(r));
}
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