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/*
* U-boot - i386 Startup Code
*
* Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
*
* 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>
#include <version.h>
#include <asm/global_data.h>
#include <asm/processor-flags.h>
.section .text
.code32
.globl _start
.type _start, @function
.globl _i386boot_start
_i386boot_start:
/*
* This is the fail safe 32-bit bootstrap entry point. The
* following code is not executed from a cold-reset (actually, a
* lot of it is, but from real-mode after cold reset. It is
* repeated here to put the board into a state as close to cold
* reset as necessary)
*/
cli
cld
/* Turn of cache (this might require a 486-class CPU) */
movl %cr0, %eax
orl $(X86_CR0_NW | X86_CR0_CD), %eax
movl %eax, %cr0
wbinvd
/* Tell 32-bit code it is being entered from an in-RAM copy */
movw $GD_FLG_WARM_BOOT, %bx
_start:
/* This is the 32-bit cold-reset entry point */
movl $0x18, %eax /* Load our segement registes, the
* gdt have already been loaded by start16.S */
movw %ax, %fs
movw %ax, %ds
movw %ax, %gs
movw %ax, %es
movw %ax, %ss
/* Clear the interupt vectors */
lidt blank_idt_ptr
/* Early platform init (setup gpio, etc ) */
jmp early_board_init
.globl early_board_init_ret
early_board_init_ret:
/* Initialise Cache-As-RAM */
jmp car_init
.globl car_init_ret
car_init_ret:
/*
* We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
* or fully initialised SDRAM - we really don't care which)
* starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
*/
movl $CONFIG_SYS_INIT_SP_ADDR, %esp
movl $CONFIG_SYS_INIT_GD_ADDR, %ebp
/* Set Boot Flags in Global Data */
movl %ebx, (GD_FLAGS * 4)(%ebp)
/* Determine our load offset (and put in Global Data) */
call 1f
1: popl %ecx
subl $1b, %ecx
movl %ecx, (GD_LOAD_OFF * 4)(%ebp)
/* Set parameter to board_init_f() to boot flags */
movl (GD_FLAGS * 4)(%ebp), %eax
call board_init_f /* Enter, U-boot! */
/* indicate (lack of) progress */
movw $0x85, %ax
jmp die
.globl relocate_code
.type relocate_code, @function
relocate_code:
/*
* SDRAM has been initialised, U-Boot code has been copied into
* RAM, BSS has been cleared and relocation adjustments have been
* made. It is now time to jump into the in-RAM copy of U-Boot
*
* %eax = Address of top of stack
* %edx = Address of Global Data
* %ecx = Base address of in-RAM copy of U-Boot
*/
/* Setup stack in RAM */
movl %eax, %esp
/* Setup call address of in-RAM copy of board_init_r() */
movl $board_init_r, %ebp
subl (GD_RELOC_OFF * 4)(%edx), %ebp
/* Setup parameters to board_init_r() */
movl %edx, %eax
movl %ecx, %edx
/* Jump to in-RAM copy of board_init_r() */
call *%ebp
die: hlt
jmp die
hlt
blank_idt_ptr:
.word 0 /* limit */
.long 0 /* base */
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