1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* U-boot - x86 Startup Code
*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@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>
#include <asm/processor-flags.h>
.section .text
.code32
.globl _start
.type _start, @function
.globl _x86boot_start
_x86boot_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 $(X86_CR0_NW | X86_CR0_CD), %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 */
/* Load the segement registes to match the gdt loaded in start16.S */
movl $0x18, %eax
movw %ax, %fs
movw %ax, %ds
movw %ax, %gs
movw %ax, %es
movw %ax, %ss
/* Clear the interupt vectors */
lidt blank_idt_ptr
/* Early platform init (setup gpio, etc ) */
jmp early_board_init
.globl early_board_init_ret
early_board_init_ret:
/* Initialise Cache-As-RAM */
jmp car_init
.globl car_init_ret
car_init_ret:
/*
* We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
* or fully initialised SDRAM - we really don't care which)
* starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
*/
movl $CONFIG_SYS_INIT_SP_ADDR, %esp
/* Set parameter to board_init_f() to boot flags */
xorl %eax, %eax
movw %bx, %ax
/* Enter, U-boot! */
call board_init_f
/* indicate (lack of) progress */
movw $0x85, %ax
jmp die
.globl relocate_code
.type relocate_code, @function
relocate_code:
/*
* SDRAM has been initialised, U-Boot code has been copied into
* RAM, BSS has been cleared and relocation adjustments have been
* made. It is now time to jump into the in-RAM copy of U-Boot
*
* %eax = Address of top of stack
* %edx = Address of Global Data
* %ecx = Base address of in-RAM copy of U-Boot
*/
/* Setup stack in RAM */
movl %eax, %esp
/* Setup call address of in-RAM copy of board_init_r() */
movl $board_init_r, %ebp
addl (GD_RELOC_OFF * 4)(%edx), %ebp
/* Setup parameters to board_init_r() */
movl %edx, %eax
movl %ecx, %edx
/* Jump to in-RAM copy of board_init_r() */
call *%ebp
die: hlt
jmp die
hlt
blank_idt_ptr:
.word 0 /* limit */
.long 0 /* base */
|
