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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/*
* prepare to run common code
*
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/percpu.h>
#include <linux/start_kernel.h>
#include <linux/io.h>
#include <asm/processor.h>
#include <asm/proto.h>
#include <asm/smp.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/kdebug.h>
#include <asm/e820.h>
#include <asm/bios_ebda.h>
/* boot cpu pda */
static struct x8664_pda _boot_cpu_pda __read_mostly;
#ifdef CONFIG_SMP
/*
* We install an empty cpu_pda pointer table to indicate to early users
* (numa_set_node) that the cpu_pda pointer table for cpus other than
* the boot cpu is not yet setup.
*/
static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
#else
static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
#endif
static void __init zap_identity_mappings(void)
{
pgd_t *pgd = pgd_offset_k(0UL);
pgd_clear(pgd);
__flush_tlb_all();
}
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
static void __init clear_bss(void)
{
memset(__bss_start, 0,
(unsigned long) __bss_stop - (unsigned long) __bss_start);
}
static void __init copy_bootdata(char *real_mode_data)
{
char * command_line;
memcpy(&boot_params, real_mode_data, sizeof boot_params);
if (boot_params.hdr.cmd_line_ptr) {
command_line = __va(boot_params.hdr.cmd_line_ptr);
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
}
}
#define BIOS_LOWMEM_KILOBYTES 0x413
/*
* The BIOS places the EBDA/XBDA at the top of conventional
* memory, and usually decreases the reported amount of
* conventional memory (int 0x12) too. This also contains a
* workaround for Dell systems that neglect to reserve EBDA.
* The same workaround also avoids a problem with the AMD768MPX
* chipset: reserve a page before VGA to prevent PCI prefetch
* into it (errata #56). Usually the page is reserved anyways,
* unless you have no PS/2 mouse plugged in.
*/
static void __init reserve_ebda_region(void)
{
unsigned int lowmem, ebda_addr;
/* To determine the position of the EBDA and the */
/* end of conventional memory, we need to look at */
/* the BIOS data area. In a paravirtual environment */
/* that area is absent. We'll just have to assume */
/* that the paravirt case can handle memory setup */
/* correctly, without our help. */
if (paravirt_enabled())
return;
/* end of low (conventional) memory */
lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
lowmem <<= 10;
/* start of EBDA area */
ebda_addr = get_bios_ebda();
/* Fixup: bios puts an EBDA in the top 64K segment */
/* of conventional memory, but does not adjust lowmem. */
if ((lowmem - ebda_addr) <= 0x10000)
lowmem = ebda_addr;
/* Fixup: bios does not report an EBDA at all. */
/* Some old Dells seem to need 4k anyhow (bugzilla 2990) */
if ((ebda_addr == 0) && (lowmem >= 0x9f000))
lowmem = 0x9f000;
/* Paranoia: should never happen, but... */
if ((lowmem == 0) || (lowmem >= 0x100000))
lowmem = 0x9f000;
/* reserve all memory between lowmem and the 1MB mark */
reserve_early(lowmem, 0x100000, "BIOS reserved");
}
static void __init reserve_setup_data(void)
{
struct setup_data *data;
unsigned long pa_data;
char buf[32];
if (boot_params.hdr.version < 0x0209)
return;
pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = early_ioremap(pa_data, sizeof(*data));
sprintf(buf, "setup data %x", data->type);
reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
pa_data = data->next;
early_iounmap(data, sizeof(*data));
}
}
void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
/*
* Build-time sanity checks on the kernel image and module
* area mappings. (these are purely build-time and produce no code)
*/
BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
(__START_KERNEL & PGDIR_MASK)));
/* clear bss before set_intr_gate with early_idt_handler */
clear_bss();
/* Make NULL pointers segfault */
zap_identity_mappings();
/* Cleanup the over mapped high alias */
cleanup_highmap();
for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
#ifdef CONFIG_EARLY_PRINTK
set_intr_gate(i, &early_idt_handlers[i]);
#else
set_intr_gate(i, early_idt_handler);
#endif
}
load_idt((const struct desc_ptr *)&idt_descr);
early_printk("Kernel alive\n");
_cpu_pda = __cpu_pda;
cpu_pda(0) = &_boot_cpu_pda;
pda_init(0);
early_printk("Kernel really alive\n");
copy_bootdata(__va(real_mode_data));
reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
#ifdef CONFIG_BLK_DEV_INITRD
/* Reserve INITRD */
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
}
#endif
reserve_ebda_region();
reserve_setup_data();
/*
* At this point everything still needed from the boot loader
* or BIOS or kernel text should be early reserved or marked not
* RAM in e820. All other memory is free game.
*/
start_kernel();
}
|
