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Commit | Line | Data |
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1da177e4 | 1 | /* |
835c34a1 | 2 | * prepare to run common code |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE | |
1da177e4 LT |
5 | */ |
6 | ||
7 | #include <linux/init.h> | |
8 | #include <linux/linkage.h> | |
9 | #include <linux/types.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/percpu.h> | |
eaf76e8b | 13 | #include <linux/start_kernel.h> |
1da177e4 LT |
14 | |
15 | #include <asm/processor.h> | |
16 | #include <asm/proto.h> | |
17 | #include <asm/smp.h> | |
1da177e4 LT |
18 | #include <asm/setup.h> |
19 | #include <asm/desc.h> | |
f6c2e333 | 20 | #include <asm/pgtable.h> |
cfd243d4 | 21 | #include <asm/tlbflush.h> |
2bc0414e | 22 | #include <asm/sections.h> |
718fc13b | 23 | #include <asm/kdebug.h> |
75175278 | 24 | #include <asm/e820.h> |
356fa0c6 | 25 | #include <asm/bios_ebda.h> |
1da177e4 | 26 | |
cfd243d4 VG |
27 | static void __init zap_identity_mappings(void) |
28 | { | |
29 | pgd_t *pgd = pgd_offset_k(0UL); | |
30 | pgd_clear(pgd); | |
cd582896 | 31 | __flush_tlb_all(); |
cfd243d4 VG |
32 | } |
33 | ||
1da177e4 LT |
34 | /* Don't add a printk in there. printk relies on the PDA which is not initialized |
35 | yet. */ | |
36 | static void __init clear_bss(void) | |
37 | { | |
1da177e4 | 38 | memset(__bss_start, 0, |
2bc0414e | 39 | (unsigned long) __bss_stop - (unsigned long) __bss_start); |
1da177e4 LT |
40 | } |
41 | ||
1da177e4 LT |
42 | static void __init copy_bootdata(char *real_mode_data) |
43 | { | |
1da177e4 LT |
44 | char * command_line; |
45 | ||
30c82645 PA |
46 | memcpy(&boot_params, real_mode_data, sizeof boot_params); |
47 | if (boot_params.hdr.cmd_line_ptr) { | |
48 | command_line = __va(boot_params.hdr.cmd_line_ptr); | |
49 | memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); | |
1da177e4 | 50 | } |
1da177e4 LT |
51 | } |
52 | ||
f6eb62b6 | 53 | #define BIOS_LOWMEM_KILOBYTES 0x413 |
75175278 | 54 | |
f6eb62b6 AH |
55 | /* |
56 | * The BIOS places the EBDA/XBDA at the top of conventional | |
57 | * memory, and usually decreases the reported amount of | |
320a6b2e AH |
58 | * conventional memory (int 0x12) too. This also contains a |
59 | * workaround for Dell systems that neglect to reserve EBDA. | |
60 | * The same workaround also avoids a problem with the AMD768MPX | |
61 | * chipset: reserve a page before VGA to prevent PCI prefetch | |
62 | * into it (errata #56). Usually the page is reserved anyways, | |
63 | * unless you have no PS/2 mouse plugged in. | |
f6eb62b6 | 64 | */ |
320a6b2e | 65 | static void __init reserve_ebda_region(void) |
75175278 | 66 | { |
f6eb62b6 | 67 | unsigned int lowmem, ebda_addr; |
75175278 | 68 | |
320a6b2e AH |
69 | /* To determine the position of the EBDA and the */ |
70 | /* end of conventional memory, we need to look at */ | |
71 | /* the BIOS data area. In a paravirtual environment */ | |
72 | /* that area is absent. We'll just have to assume */ | |
73 | /* that the paravirt case can handle memory setup */ | |
74 | /* correctly, without our help. */ | |
ecd94c08 | 75 | if (paravirt_enabled()) |
320a6b2e | 76 | return; |
320a6b2e | 77 | |
f6eb62b6 AH |
78 | /* end of low (conventional) memory */ |
79 | lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES); | |
80 | lowmem <<= 10; | |
81 | ||
82 | /* start of EBDA area */ | |
356fa0c6 | 83 | ebda_addr = get_bios_ebda(); |
75175278 | 84 | |
f6eb62b6 AH |
85 | /* Fixup: bios puts an EBDA in the top 64K segment */ |
86 | /* of conventional memory, but does not adjust lowmem. */ | |
87 | if ((lowmem - ebda_addr) <= 0x10000) | |
88 | lowmem = ebda_addr; | |
75175278 | 89 | |
f6eb62b6 AH |
90 | /* Fixup: bios does not report an EBDA at all. */ |
91 | /* Some old Dells seem to need 4k anyhow (bugzilla 2990) */ | |
92 | if ((ebda_addr == 0) && (lowmem >= 0x9f000)) | |
93 | lowmem = 0x9f000; | |
75175278 | 94 | |
f6eb62b6 | 95 | /* Paranoia: should never happen, but... */ |
320a6b2e AH |
96 | if ((lowmem == 0) || (lowmem >= 0x100000)) |
97 | lowmem = 0x9f000; | |
75175278 | 98 | |
f6eb62b6 AH |
99 | /* reserve all memory between lowmem and the 1MB mark */ |
100 | reserve_early(lowmem, 0x100000, "BIOS reserved"); | |
75175278 AK |
101 | } |
102 | ||
1da177e4 LT |
103 | void __init x86_64_start_kernel(char * real_mode_data) |
104 | { | |
1da177e4 LT |
105 | int i; |
106 | ||
b4e0409a IM |
107 | /* |
108 | * Build-time sanity checks on the kernel image and module | |
109 | * area mappings. (these are purely build-time and produce no code) | |
110 | */ | |
111 | BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START); | |
112 | BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE); | |
113 | BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); | |
114 | BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0); | |
115 | BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); | |
116 | BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); | |
117 | BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == | |
118 | (__START_KERNEL & PGDIR_MASK))); | |
119 | ||
3df0af0e YL |
120 | /* clear bss before set_intr_gate with early_idt_handler */ |
121 | clear_bss(); | |
122 | ||
cfd243d4 VG |
123 | /* Make NULL pointers segfault */ |
124 | zap_identity_mappings(); | |
125 | ||
31eedd82 TG |
126 | /* Cleanup the over mapped high alias */ |
127 | cleanup_highmap(); | |
128 | ||
5524ea32 | 129 | for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { |
076f9776 | 130 | #ifdef CONFIG_EARLY_PRINTK |
8866cd9d | 131 | set_intr_gate(i, &early_idt_handlers[i]); |
076f9776 IM |
132 | #else |
133 | set_intr_gate(i, early_idt_handler); | |
134 | #endif | |
135 | } | |
9d1c6e7c | 136 | load_idt((const struct desc_ptr *)&idt_descr); |
f6c2e333 | 137 | |
43c85c9c | 138 | early_printk("Kernel alive\n"); |
2148270c | 139 | |
365ba917 RT |
140 | for (i = 0; i < NR_CPUS; i++) |
141 | cpu_pda(i) = &boot_cpu_pda[i]; | |
142 | ||
1da177e4 | 143 | pda_init(0); |
278c0eb7 | 144 | copy_bootdata(__va(real_mode_data)); |
9de819fe | 145 | |
25eff8d4 | 146 | reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS"); |
75175278 | 147 | |
2b8106a0 | 148 | #ifdef CONFIG_BLK_DEV_INITRD |
75175278 AK |
149 | /* Reserve INITRD */ |
150 | if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) { | |
151 | unsigned long ramdisk_image = boot_params.hdr.ramdisk_image; | |
152 | unsigned long ramdisk_size = boot_params.hdr.ramdisk_size; | |
153 | unsigned long ramdisk_end = ramdisk_image + ramdisk_size; | |
25eff8d4 | 154 | reserve_early(ramdisk_image, ramdisk_end, "RAMDISK"); |
75175278 | 155 | } |
2b8106a0 | 156 | #endif |
75175278 | 157 | |
320a6b2e | 158 | reserve_ebda_region(); |
75175278 AK |
159 | |
160 | /* | |
161 | * At this point everything still needed from the boot loader | |
162 | * or BIOS or kernel text should be early reserved or marked not | |
163 | * RAM in e820. All other memory is free game. | |
164 | */ | |
165 | ||
1da177e4 LT |
166 | start_kernel(); |
167 | } |