mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-25 22:20:45 +00:00
196 lines
4.2 KiB
ArmAsm
196 lines
4.2 KiB
ArmAsm
/*
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* U-boot - i386 Startup Code
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*
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* Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <config.h>
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#include <version.h>
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.section .text
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.code32
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.globl _start
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.type _start, @function
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.globl _i386boot_start
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_i386boot_start:
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_start:
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movl $0x18,%eax /* Load our segement registes, the
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* gdt have already been loaded by start16.S */
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movw %ax,%fs
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movw %ax,%ds
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movw %ax,%gs
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movw %ax,%es
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movw %ax,%ss
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/* We call a few functions in the board support package
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* since we have no stack yet we'll have to use %ebp
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* to store the return address */
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/* Early platform init (setup gpio, etc ) */
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mov $early_board_init_ret, %ebp
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jmp early_board_init
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early_board_init_ret:
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/* The __port80 entry-point should be usabe by now */
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/* so we try to indicate progress */
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movw $0x01, %ax
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movl $.progress0, %ebp
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jmp show_boot_progress
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.progress0:
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/* size memory */
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mov $mem_init_ret, %ebp
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jmp mem_init
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mem_init_ret:
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/* check ammount of configured memory
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* (we need atleast bss start+bss size+stack size) */
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movl $_i386boot_bss_start, %ecx /* BSS start */
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addl $_i386boot_bss_size, %ecx /* BSS size */
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addl $CONFIG_SYS_STACK_SIZE, %ecx
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cmpl %ecx, %eax
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jae mem_ok
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/* indicate (lack of) progress */
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movw $0x81, %ax
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movl $.progress0a, %ebp
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jmp show_boot_progress
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.progress0a:
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jmp die
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mem_ok:
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/* indicate progress */
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movw $0x02, %ax
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movl $.progress1, %ebp
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jmp show_boot_progress
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.progress1:
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/* create a stack after the bss */
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movl $_i386boot_bss_start, %eax
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addl $_i386boot_bss_size, %eax
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addl $CONFIG_SYS_STACK_SIZE, %eax
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movl %eax, %esp
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pushl $0
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popl %eax
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cmpl $0, %eax
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jne no_stack
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push $0x55aa55aa
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popl %ebx
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cmpl $0x55aa55aa, %ebx
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je stack_ok
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no_stack:
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/* indicate (lack of) progress */
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movw $0x82, %ax
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movl $.progress1a, %ebp
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jmp show_boot_progress
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.progress1a:
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jmp die
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stack_ok:
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/* indicate progress */
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movw $0x03, %ax
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movl $.progress2, %ebp
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jmp show_boot_progress
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.progress2:
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/* copy data section to ram, size must be 4-byte aligned */
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movl $_i386boot_romdata_dest, %edi /* destination address */
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movl $_i386boot_romdata_start, %esi /* source address */
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movl $_i386boot_romdata_size, %ecx /* number of bytes to copy */
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movl %ecx, %eax
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andl $3, %eax
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jnz data_fail
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shrl $2, %ecx /* copy 4 byte each time */
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cld
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cmpl $0, %ecx
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je data_ok
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data_segment:
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movsl
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loop data_segment
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jmp data_ok
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data_fail:
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/* indicate (lack of) progress */
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movw $0x83, %ax
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movl $.progress2a, %ebp
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jmp show_boot_progress
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.progress2a:
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jmp die
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data_ok:
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/* indicate progress */
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movw $0x04, %ax
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movl $.progress3, %ebp
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jmp show_boot_progress
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.progress3:
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/* clear bss section in ram, size must be 4-byte aligned */
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movl $_i386boot_bss_start, %edi /* MK_CHG BSS start */
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movl $_i386boot_bss_size, %ecx /* BSS size */
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movl %ecx, %eax
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andl $3, %eax
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jnz bss_fail
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shrl $2, %ecx /* clear 4 byte each time */
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cld
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cmpl $0, %ecx
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je bss_ok
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bss:
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movl $0, (%edi)
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add $4, %edi
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loop bss
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jmp bss_ok
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bss_fail:
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/* indicate (lack of) progress */
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movw $0x84, %ax
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movl $.progress3a, %ebp
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jmp show_boot_progress
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.progress3a:
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jmp die
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bss_ok:
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wbinvd
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/* indicate progress */
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movw $0x05, %ax
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movl $.progress4, %ebp
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jmp show_boot_progress
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.progress4:
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call start_i386boot /* Enter, U-boot! */
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/* indicate (lack of) progress */
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movw $0x85, %ax
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movl $.progress4a, %ebp
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jmp show_boot_progress
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.progress4a:
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die: hlt
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jmp die
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hlt
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