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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
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +020058 jmp show_boot_progress
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
66 /* check ammount of configured memory
67 * (we need atleast bss start+bss size+stack size) */
wdenk2262cfe2002-11-18 00:14:45 +000068 movl $_i386boot_bss_start, %ecx /* BSS start */
wdenk8bde7f72003-06-27 21:31:46 +000069 addl $_i386boot_bss_size, %ecx /* BSS size */
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +020070 addl $CONFIG_SYS_STACK_SIZE, %ecx
wdenk8bde7f72003-06-27 21:31:46 +000071 cmpl %ecx, %eax
wdenk2262cfe2002-11-18 00:14:45 +000072 jae mem_ok
wdenk8bde7f72003-06-27 21:31:46 +000073
wdenk2262cfe2002-11-18 00:14:45 +000074 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +000075 movw $0x81, %ax
wdenk2262cfe2002-11-18 00:14:45 +000076 movl $.progress0a, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +020077 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +000078.progress0a:
Wolfgang Denk53677ef2008-05-20 16:00:29 +020079 jmp die
wdenk8bde7f72003-06-27 21:31:46 +000080mem_ok:
wdenk2262cfe2002-11-18 00:14:45 +000081
82 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +000083 movw $0x02, %ax
wdenk2262cfe2002-11-18 00:14:45 +000084 movl $.progress1, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +020085 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +000086.progress1:
wdenk2262cfe2002-11-18 00:14:45 +000087
88 /* create a stack after the bss */
wdenk8bde7f72003-06-27 21:31:46 +000089 movl $_i386boot_bss_start, %eax
wdenk2262cfe2002-11-18 00:14:45 +000090 addl $_i386boot_bss_size, %eax
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +020091 addl $CONFIG_SYS_STACK_SIZE, %eax
wdenk8bde7f72003-06-27 21:31:46 +000092 movl %eax, %esp
93
wdenk2262cfe2002-11-18 00:14:45 +000094 pushl $0
95 popl %eax
96 cmpl $0, %eax
97 jne no_stack
98 push $0x55aa55aa
99 popl %ebx
100 cmpl $0x55aa55aa, %ebx
101 je stack_ok
102
103no_stack:
104 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +0000105 movw $0x82, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000106 movl $.progress1a, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200107 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +0000108.progress1a:
wdenk2262cfe2002-11-18 00:14:45 +0000109 jmp die
wdenk8bde7f72003-06-27 21:31:46 +0000110
111
112stack_ok:
wdenk2262cfe2002-11-18 00:14:45 +0000113 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +0000114 movw $0x03, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000115 movl $.progress2, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200116 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +0000117.progress2:
wdenk2262cfe2002-11-18 00:14:45 +0000118
119 /* copy data section to ram, size must be 4-byte aligned */
120 movl $_i386boot_romdata_dest, %edi /* destination address */
wdenk8bde7f72003-06-27 21:31:46 +0000121 movl $_i386boot_romdata_start, %esi /* source address */
wdenk2262cfe2002-11-18 00:14:45 +0000122 movl $_i386boot_romdata_size, %ecx /* number of bytes to copy */
123 movl %ecx, %eax
124 andl $3, %eax
125 jnz data_fail
wdenk8bde7f72003-06-27 21:31:46 +0000126
wdenk2262cfe2002-11-18 00:14:45 +0000127 shrl $2, %ecx /* copy 4 byte each time */
wdenk8bde7f72003-06-27 21:31:46 +0000128 cld
wdenk2262cfe2002-11-18 00:14:45 +0000129 cmpl $0, %ecx
wdenk8bde7f72003-06-27 21:31:46 +0000130 je data_ok
131data_segment:
132 movsl
wdenk2262cfe2002-11-18 00:14:45 +0000133 loop data_segment
134 jmp data_ok
135data_fail:
136 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +0000137 movw $0x83, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000138 movl $.progress2a, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200139 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +0000140.progress2a:
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200141 jmp die
wdenk2262cfe2002-11-18 00:14:45 +0000142
wdenk8bde7f72003-06-27 21:31:46 +0000143data_ok:
wdenk2262cfe2002-11-18 00:14:45 +0000144
145 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +0000146 movw $0x04, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000147 movl $.progress3, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200148 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +0000149.progress3:
wdenk2262cfe2002-11-18 00:14:45 +0000150
151 /* clear bss section in ram, size must be 4-byte aligned */
mushtaq khan644e6fb2007-04-30 15:57:22 +0530152 movl $_i386boot_bss_start, %edi /* MK_CHG BSS start */
wdenk8bde7f72003-06-27 21:31:46 +0000153 movl $_i386boot_bss_size, %ecx /* BSS size */
wdenk2262cfe2002-11-18 00:14:45 +0000154 movl %ecx, %eax
155 andl $3, %eax
156 jnz bss_fail
157 shrl $2, %ecx /* clear 4 byte each time */
wdenk8bde7f72003-06-27 21:31:46 +0000158 cld
wdenk2262cfe2002-11-18 00:14:45 +0000159 cmpl $0, %ecx
wdenk8bde7f72003-06-27 21:31:46 +0000160 je bss_ok
161bss:
wdenk2262cfe2002-11-18 00:14:45 +0000162 movl $0, (%edi)
wdenk8bde7f72003-06-27 21:31:46 +0000163 add $4, %edi
wdenk2262cfe2002-11-18 00:14:45 +0000164 loop bss
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200165 jmp bss_ok
wdenk2262cfe2002-11-18 00:14:45 +0000166
167bss_fail:
168 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +0000169 movw $0x84, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000170 movl $.progress3a, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200171 jmp show_boot_progress
wdenk8bde7f72003-06-27 21:31:46 +0000172.progress3a:
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200173 jmp die
wdenk2262cfe2002-11-18 00:14:45 +0000174
wdenk8bde7f72003-06-27 21:31:46 +0000175bss_ok:
wdenk2262cfe2002-11-18 00:14:45 +0000176
wdenk8bde7f72003-06-27 21:31:46 +0000177 wbinvd
wdenk2262cfe2002-11-18 00:14:45 +0000178
179
180 /* indicate progress */
wdenk8bde7f72003-06-27 21:31:46 +0000181 movw $0x05, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000182 movl $.progress4, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200183 jmp show_boot_progress
wdenk2262cfe2002-11-18 00:14:45 +0000184.progress4:
185
186 call start_i386boot /* Enter, U-boot! */
187
188 /* indicate (lack of) progress */
wdenk8bde7f72003-06-27 21:31:46 +0000189 movw $0x85, %ax
wdenk2262cfe2002-11-18 00:14:45 +0000190 movl $.progress4a, %ebp
Jean-Christophe PLAGNIOL-VILLARD3cc27b42008-05-18 19:09:58 +0200191 jmp show_boot_progress
wdenk2262cfe2002-11-18 00:14:45 +0000192.progress4a:
193
194die: hlt
195 jmp die
wdenk8bde7f72003-06-27 21:31:46 +0000196 hlt