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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>
.section .text
.code32
.globl _start
.type _start, @function
.globl _i386boot_start
_i386boot_start:
_start:
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
/* We call a few functions in the board support package
* since we have no stack yet we'll have to use %ebp
* to store the return address */
/* Early platform init (setup gpio, etc ) */
mov $early_board_init_ret, %ebp
jmp early_board_init
early_board_init_ret:
/* The __port80 entry-point should be usabe by now */
/* so we try to indicate progress */
movw $0x01, %ax
movl $.progress0, %ebp
jmp show_boot_progress_asm
.progress0:
/* size memory */
mov $mem_init_ret, %ebp
jmp mem_init
mem_init_ret:
/* check ammount of configured memory
* (we need atleast bss start+bss size+stack size) */
movl $_i386boot_bss_start, %ecx /* BSS start */
addl $_i386boot_bss_size, %ecx /* BSS size */
addl $CONFIG_SYS_STACK_SIZE, %ecx
cmpl %ecx, %eax
jae mem_ok
/* indicate (lack of) progress */
movw $0x81, %ax
movl $.progress0a, %ebp
jmp show_boot_progress_asm
.progress0a:
jmp die
mem_ok:
/* indicate progress */
movw $0x02, %ax
movl $.progress1, %ebp
jmp show_boot_progress_asm
.progress1:
/* create a stack after the bss */
movl $_i386boot_bss_start, %eax
addl $_i386boot_bss_size, %eax
addl $CONFIG_SYS_STACK_SIZE, %eax
movl %eax, %esp
pushl $0
popl %eax
cmpl $0, %eax
jne no_stack
push $0x55aa55aa
popl %ebx
cmpl $0x55aa55aa, %ebx
je stack_ok
no_stack:
/* indicate (lack of) progress */
movw $0x82, %ax
movl $.progress1a, %ebp
jmp show_boot_progress_asm
.progress1a:
jmp die
stack_ok:
/* indicate progress */
movw $0x03, %ax
movl $.progress2, %ebp
jmp show_boot_progress_asm
.progress2:
/* copy data section to ram, size must be 4-byte aligned */
movl $_i386boot_romdata_dest, %edi /* destination address */
movl $_i386boot_romdata_start, %esi /* source address */
movl $_i386boot_romdata_size, %ecx /* number of bytes to copy */
movl %ecx, %eax
andl $3, %eax
jnz data_fail
shrl $2, %ecx /* copy 4 byte each time */
cld
cmpl $0, %ecx
je data_ok
data_segment:
movsl
loop data_segment
jmp data_ok
data_fail:
/* indicate (lack of) progress */
movw $0x83, %ax
movl $.progress2a, %ebp
jmp show_boot_progress_asm
.progress2a:
jmp die
data_ok:
/* indicate progress */
movw $0x04, %ax
movl $.progress3, %ebp
jmp show_boot_progress_asm
.progress3:
/* clear bss section in ram, size must be 4-byte aligned */
movl $_i386boot_bss_start, %edi /* MK_CHG BSS start */
movl $_i386boot_bss_size, %ecx /* BSS size */
movl %ecx, %eax
andl $3, %eax
jnz bss_fail
shrl $2, %ecx /* clear 4 byte each time */
cld
cmpl $0, %ecx
je bss_ok
bss:
movl $0, (%edi)
add $4, %edi
loop bss
jmp bss_ok
bss_fail:
/* indicate (lack of) progress */
movw $0x84, %ax
movl $.progress3a, %ebp
jmp show_boot_progress_asm
.progress3a:
jmp die
bss_ok:
wbinvd
/* indicate progress */
movw $0x05, %ax
movl $.progress4, %ebp
jmp show_boot_progress_asm
.progress4:
call start_i386boot /* Enter, U-boot! */
/* indicate (lack of) progress */
movw $0x85, %ax
movl $.progress4a, %ebp
jmp show_boot_progress_asm
.progress4a:
die: hlt
jmp die
hlt
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