148 lines
3.3 KiB
ArmAsm
148 lines
3.3 KiB
ArmAsm
/*
|
||
* U-boot - i386 Startup Code
|
||
*
|
||
* Copyright (c) 2002 Omicron Ceti AB, Daniel Engstr<EFBFBD>m <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>
|
||
|
||
|
||
.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 $0x60000000, %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
|
||
|
||
/* Skip low-level initialization if not starting from cold-reset */
|
||
movl %ebx, %ecx
|
||
andl $GD_FLG_COLD_BOOT, %ecx
|
||
jz skip_mem_init
|
||
|
||
/* Early platform init (setup gpio, etc ) */
|
||
jmp early_board_init
|
||
.globl early_board_init_ret
|
||
early_board_init_ret:
|
||
|
||
/* size memory */
|
||
jmp mem_init
|
||
.globl mem_init_ret
|
||
mem_init_ret:
|
||
|
||
skip_mem_init:
|
||
/* fetch memory size (into %eax) */
|
||
jmp get_mem_size
|
||
.globl get_mem_size_ret
|
||
get_mem_size_ret:
|
||
|
||
#if CONFIG_SYS_SDRAM_ECC_ENABLE
|
||
/* Skip ECC initialization if not starting from cold-reset */
|
||
movl %ebx, %ecx
|
||
andl $GD_FLG_COLD_BOOT, %ecx
|
||
jz init_ecc_ret
|
||
jmp init_ecc
|
||
|
||
.globl init_ecc_ret
|
||
init_ecc_ret:
|
||
#endif
|
||
|
||
/* Check we have enough memory for stack */
|
||
movl $CONFIG_SYS_STACK_SIZE, %ecx
|
||
cmpl %ecx, %eax
|
||
jb die
|
||
mem_ok:
|
||
/* Set stack pointer to upper memory limit*/
|
||
movl %eax, %esp
|
||
|
||
/* Test the stack */
|
||
pushl $0
|
||
popl %ecx
|
||
cmpl $0, %ecx
|
||
jne die
|
||
push $0x55aa55aa
|
||
popl %ecx
|
||
cmpl $0x55aa55aa, %ecx
|
||
jne die
|
||
|
||
wbinvd
|
||
|
||
/* Determine our load offset */
|
||
call 1f
|
||
1: popl %ecx
|
||
subl $1b, %ecx
|
||
|
||
/* Set the upper memory limit parameter */
|
||
subl $CONFIG_SYS_STACK_SIZE, %eax
|
||
|
||
/* Reserve space for global data */
|
||
subl $(GD_SIZE * 4), %eax
|
||
|
||
/* %eax points to the global data structure */
|
||
movl %esp, (GD_RAM_SIZE * 4)(%eax)
|
||
movl %ebx, (GD_FLAGS * 4)(%eax)
|
||
movl %ecx, (GD_LOAD_OFF * 4)(%eax)
|
||
|
||
call board_init_f /* Enter, U-boot! */
|
||
|
||
/* indicate (lack of) progress */
|
||
movw $0x85, %ax
|
||
die: hlt
|
||
jmp die
|
||
hlt
|
||
|
||
blank_idt_ptr:
|
||
.word 0 /* limit */
|
||
.long 0 /* base */
|