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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* 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 <common.h>
#include <command.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <asm/interrupt.h>
/*
* Constructor for a conventional segment GDT (or LDT) entry
* This is a macro so it can be used in initialisers
*/
#define GDT_ENTRY(flags, base, limit) \
((((base) & 0xff000000ULL) << (56-24)) | \
(((flags) & 0x0000f0ffULL) << 40) | \
(((limit) & 0x000f0000ULL) << (48-16)) | \
(((base) & 0x00ffffffULL) << 16) | \
(((limit) & 0x0000ffffULL)))
struct gdt_ptr {
u16 len;
u32 ptr;
} __packed;
static void reload_gdt(void)
{
/*
* There are machines which are known to not boot with the GDT
* being 8-byte unaligned. Intel recommends 16 byte alignment
*/
static const u64 boot_gdt[] __attribute__((aligned(16))) = {
/* CS: code, read/execute, 4 GB, base 0 */
[GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
/* DS: data, read/write, 4 GB, base 0 */
[GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
/* 16-bit CS: code, read/execute, 64 kB, base 0 */
[GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
/* 16-bit DS: data, read/write, 64 kB, base 0 */
[GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
};
static struct gdt_ptr gdt;
gdt.len = sizeof(boot_gdt)-1;
gdt.ptr = (u32)&boot_gdt;
asm volatile("lgdtl %0\n" \
"movl $((2+1)*8), %%ecx\n" \
"movl %%ecx, %%ds\n" \
"movl %%ecx, %%es\n" \
"movl %%ecx, %%fs\n" \
"movl %%ecx, %%gs\n" \
"movl %%ecx, %%ss" \
: : "m" (gdt) : "ecx");
}
int x86_cpu_init_f(void)
{
const u32 em_rst = ~X86_CR0_EM;
const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
/* initialize FPU, reset EM, set MP and NE */
asm ("fninit\n" \
"movl %%cr0, %%eax\n" \
"andl %0, %%eax\n" \
"orl %1, %%eax\n" \
"movl %%eax, %%cr0\n" \
: : "i" (em_rst), "i" (mp_ne_set) : "eax");
return 0;
}
int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
int x86_cpu_init_r(void)
{
const u32 nw_cd_rst = ~(X86_CR0_NW | X86_CR0_CD);
/* turn on the cache and disable write through */
asm("movl %%cr0, %%eax\n"
"andl %0, %%eax\n"
"movl %%eax, %%cr0\n"
"wbinvd\n" : : "i" (nw_cd_rst) : "eax");
reload_gdt();
/* Initialize core interrupt and exception functionality of CPU */
cpu_init_interrupts();
return 0;
}
int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
printf("resetting ...\n");
/* wait 50 ms */
udelay(50000);
disable_interrupts();
reset_cpu(0);
/*NOTREACHED*/
return 0;
}
void flush_cache(unsigned long dummy1, unsigned long dummy2)
{
asm("wbinvd\n");
}
void __attribute__ ((regparm(0))) generate_gpf(void);
/* segment 0x70 is an arbitrary segment which does not exist */
asm(".globl generate_gpf\n"
".hidden generate_gpf\n"
".type generate_gpf, @function\n"
"generate_gpf:\n"
"ljmp $0x70, $0x47114711\n");
void __reset_cpu(ulong addr)
{
printf("Resetting using x86 Triple Fault\n");
set_vector(13, generate_gpf); /* general protection fault handler */
set_vector(8, generate_gpf); /* double fault handler */
generate_gpf(); /* start the show */
}
void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
|
