1 /*
2 * prepare to run common code
3 *
4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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>
13 #include <linux/start_kernel.h>
14 #include <linux/io.h>
15 #include <linux/memblock.h>
16
17 #include <asm/processor.h>
18 #include <asm/proto.h>
19 #include <asm/smp.h>
20 #include <asm/setup.h>
21 #include <asm/desc.h>
22 #include <asm/pgtable.h>
23 #include <asm/tlbflush.h>
24 #include <asm/sections.h>
25 #include <asm/kdebug.h>
26 #include <asm/e820.h>
27 #include <asm/trampoline.h>
28 #include <asm/bios_ebda.h>
29
zap_identity_mappings(void)30 static void __init zap_identity_mappings(void)
31 {
32 pgd_t *pgd = pgd_offset_k(0UL);
33 pgd_clear(pgd);
34 __flush_tlb_all();
35 }
36
37 /* Don't add a printk in there. printk relies on the PDA which is not initialized
38 yet. */
clear_bss(void)39 static void __init clear_bss(void)
40 {
41 memset(__bss_start, 0,
42 (unsigned long) __bss_stop - (unsigned long) __bss_start);
43 }
44
copy_bootdata(char * real_mode_data)45 static void __init copy_bootdata(char *real_mode_data)
46 {
47 char * command_line;
48
49 memcpy(&boot_params, real_mode_data, sizeof boot_params);
50 if (boot_params.hdr.cmd_line_ptr) {
51 command_line = __va(boot_params.hdr.cmd_line_ptr);
52 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
53 }
54 }
55
x86_64_start_kernel(char * real_mode_data)56 void __init x86_64_start_kernel(char * real_mode_data)
57 {
58 int i;
59
60 /*
61 * Build-time sanity checks on the kernel image and module
62 * area mappings. (these are purely build-time and produce no code)
63 */
64 BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
65 BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
66 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
67 BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
68 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
69 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
70 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
71 (__START_KERNEL & PGDIR_MASK)));
72 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
73
74 /* clear bss before set_intr_gate with early_idt_handler */
75 clear_bss();
76
77 /* Make NULL pointers segfault */
78 zap_identity_mappings();
79
80 max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;
81
82 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
83 #ifdef CONFIG_EARLY_PRINTK
84 set_intr_gate(i, &early_idt_handlers[i]);
85 #else
86 set_intr_gate(i, early_idt_handler);
87 #endif
88 }
89 load_idt((const struct desc_ptr *)&idt_descr);
90
91 if (console_loglevel == 10)
92 early_printk("Kernel alive\n");
93
94 x86_64_start_reservations(real_mode_data);
95 }
96
x86_64_start_reservations(char * real_mode_data)97 void __init x86_64_start_reservations(char *real_mode_data)
98 {
99 copy_bootdata(__va(real_mode_data));
100
101 memblock_reserve(__pa_symbol(&_text),
102 __pa_symbol(&__bss_stop) - __pa_symbol(&_text));
103
104 #ifdef CONFIG_BLK_DEV_INITRD
105 /* Reserve INITRD */
106 if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
107 /* Assume only end is not page aligned */
108 unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
109 unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
110 unsigned long ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
111 memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
112 }
113 #endif
114
115 reserve_ebda_region();
116
117 /*
118 * At this point everything still needed from the boot loader
119 * or BIOS or kernel text should be early reserved or marked not
120 * RAM in e820. All other memory is free game.
121 */
122
123 start_kernel();
124 }
125