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wdenk2262cfe2002-11-18 00:14:45 +00001/*
wdenk8bde7f72003-06-27 21:31:46 +00002 * U-boot - i386 Startup Code
wdenk2262cfe2002-11-18 00:14:45 +00003 *
4 * Copyright (c) 2002 Omicron Ceti AB, Daniel Engström <denaiel@omicron.se>
5 *
6 * See file CREDITS for list of people who contributed to this
7 * project.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * MA 02111-1307 USA
23 */
24
25
26#include <config.h>
27#include <version.h>
28
wdenk8bde7f72003-06-27 21:31:46 +000029
wdenk2262cfe2002-11-18 00:14:45 +000030.section .text
31.code32
32.globl _start
wdenk8bde7f72003-06-27 21:31:46 +000033.type _start, @function
wdenk2262cfe2002-11-18 00:14:45 +000034.globl _i386boot_start
35_i386boot_start:
wdenk8bde7f72003-06-27 21:31:46 +000036_start:
Wolfgang Denk53677ef2008-05-20 16:00:29 +020037 movl $0x18,%eax /* Load our segement registes, the
38 * gdt have already been loaded by start16.S */
wdenk8bde7f72003-06-27 21:31:46 +000039 movw %ax,%fs
wdenk2262cfe2002-11-18 00:14:45 +000040 movw %ax,%ds
wdenk8bde7f72003-06-27 21:31:46 +000041 movw %ax,%gs
42 movw %ax,%es
43 movw %ax,%ss
44
wdenk2262cfe2002-11-18 00:14:45 +000045 /* We call a few functions in the board support package
46 * since we have no stack yet we'll have to use %ebp
47 * to store the return address */
wdenk8bde7f72003-06-27 21:31:46 +000048
wdenk2262cfe2002-11-18 00:14:45 +000049 /* Early platform init (setup gpio, etc ) */
50 mov $early_board_init_ret, %ebp
51 jmp early_board_init
52early_board_init_ret:
wdenk8bde7f72003-06-27 21:31:46 +000053
wdenk2262cfe2002-11-18 00:14:45 +000054 /* The __port80 entry-point should be usabe by now */
55 /* so we try to indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +000056 movw $0x01, %ax
wdenk2262cfe2002-11-18 00:14:45 +000057 movl $.progress0, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +100058 jmp show_boot_progress_asm
wdenk8bde7f72003-06-27 21:31:46 +000059.progress0:
wdenk2262cfe2002-11-18 00:14:45 +000060
61 /* size memory */
62 mov $mem_init_ret, %ebp
wdenk8bde7f72003-06-27 21:31:46 +000063 jmp mem_init
wdenk2262cfe2002-11-18 00:14:45 +000064mem_init_ret:
wdenk8bde7f72003-06-27 21:31:46 +000065
Graeme Russ1c409bc2009-11-24 20:04:21 +110066 /* Check we have enough memory for stack */
67 movl $CONFIG_SYS_STACK_SIZE, %ecx
wdenk8bde7f72003-06-27 21:31:46 +000068 cmpl %ecx, %eax
wdenk2262cfe2002-11-18 00:14:45 +000069 jae mem_ok
wdenk8bde7f72003-06-27 21:31:46 +000070
wdenk2262cfe2002-11-18 00:14:45 +000071 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +000072 movw $0x81, %ax
wdenk2262cfe2002-11-18 00:14:45 +000073 movl $.progress0a, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +100074 jmp show_boot_progress_asm
wdenk8bde7f72003-06-27 21:31:46 +000075.progress0a:
Wolfgang Denk53677ef2008-05-20 16:00:29 +020076 jmp die
wdenk8bde7f72003-06-27 21:31:46 +000077mem_ok:
Graeme Russ1c409bc2009-11-24 20:04:21 +110078 /* Set stack pointer to upper memory limit*/
79 movl %eax, %esp
wdenk2262cfe2002-11-18 00:14:45 +000080
81 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +000082 movw $0x02, %ax
wdenk2262cfe2002-11-18 00:14:45 +000083 movl $.progress1, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +100084 jmp show_boot_progress_asm
wdenk8bde7f72003-06-27 21:31:46 +000085.progress1:
wdenk2262cfe2002-11-18 00:14:45 +000086
Graeme Russ1c409bc2009-11-24 20:04:21 +110087 /* Test the stack */
wdenk2262cfe2002-11-18 00:14:45 +000088 pushl $0
89 popl %eax
90 cmpl $0, %eax
91 jne no_stack
92 push $0x55aa55aa
93 popl %ebx
94 cmpl $0x55aa55aa, %ebx
95 je stack_ok
96
97no_stack:
98 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +000099 movw $0x82, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000100 movl $.progress1a, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +1000101 jmp show_boot_progress_asm
wdenk8bde7f72003-06-27 21:31:46 +0000102.progress1a:
wdenk2262cfe2002-11-18 00:14:45 +0000103 jmp die
wdenk8bde7f72003-06-27 21:31:46 +0000104
105
106stack_ok:
wdenk2262cfe2002-11-18 00:14:45 +0000107 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +0000108 movw $0x03, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000109 movl $.progress2, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +1000110 jmp show_boot_progress_asm
wdenk8bde7f72003-06-27 21:31:46 +0000111.progress2:
wdenk2262cfe2002-11-18 00:14:45 +0000112
wdenk8bde7f72003-06-27 21:31:46 +0000113 wbinvd
wdenk2262cfe2002-11-18 00:14:45 +0000114
Graeme Russ1c409bc2009-11-24 20:04:21 +1100115 /* Get upper memory limit */
116 movl %esp, %ecx
117 subl $CONFIG_SYS_STACK_SIZE, %ecx
wdenk2262cfe2002-11-18 00:14:45 +0000118
Graeme Russ1c409bc2009-11-24 20:04:21 +1100119 /* Create a Stack Frame */
120 pushl %ebp
121 movl %esp, %ebp
wdenk2262cfe2002-11-18 00:14:45 +0000122
Graeme Russ1c409bc2009-11-24 20:04:21 +1100123 /* stack_limit parameter */
124 pushl %ecx
125 call board_init_f /* Enter, U-boot! */
wdenk2262cfe2002-11-18 00:14:45 +0000126
127 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +0000128 movw $0x85, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000129 movl $.progress4a, %ebp
Graeme Russa369f4a2008-09-29 23:03:14 +1000130 jmp show_boot_progress_asm
wdenk2262cfe2002-11-18 00:14:45 +0000131.progress4a:
132
133die: hlt
134 jmp die
wdenk8bde7f72003-06-27 21:31:46 +0000135 hlt