linux/arch/x86/kernel/head64.c
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   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
  16#include <asm/processor.h>
  17#include <asm/proto.h>
  18#include <asm/smp.h>
  19#include <asm/setup.h>
  20#include <asm/desc.h>
  21#include <asm/pgtable.h>
  22#include <asm/tlbflush.h>
  23#include <asm/sections.h>
  24#include <asm/kdebug.h>
  25#include <asm/e820.h>
  26#include <asm/bios_ebda.h>
  27#include <asm/trampoline.h>
  28
  29/* boot cpu pda */
  30static struct x8664_pda _boot_cpu_pda;
  31
  32#ifdef CONFIG_SMP
  33/*
  34 * We install an empty cpu_pda pointer table to indicate to early users
  35 * (numa_set_node) that the cpu_pda pointer table for cpus other than
  36 * the boot cpu is not yet setup.
  37 */
  38static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
  39#else
  40static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
  41#endif
  42
  43void __init x86_64_init_pda(void)
  44{
  45        _cpu_pda = __cpu_pda;
  46        cpu_pda(0) = &_boot_cpu_pda;
  47        pda_init(0);
  48}
  49
  50static void __init zap_identity_mappings(void)
  51{
  52        pgd_t *pgd = pgd_offset_k(0UL);
  53        pgd_clear(pgd);
  54        __flush_tlb_all();
  55}
  56
  57/* Don't add a printk in there. printk relies on the PDA which is not initialized 
  58   yet. */
  59static void __init clear_bss(void)
  60{
  61        memset(__bss_start, 0,
  62               (unsigned long) __bss_stop - (unsigned long) __bss_start);
  63}
  64
  65static void __init copy_bootdata(char *real_mode_data)
  66{
  67        char * command_line;
  68
  69        memcpy(&boot_params, real_mode_data, sizeof boot_params);
  70        if (boot_params.hdr.cmd_line_ptr) {
  71                command_line = __va(boot_params.hdr.cmd_line_ptr);
  72                memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
  73        }
  74}
  75
  76void __init x86_64_start_kernel(char * real_mode_data)
  77{
  78        int i;
  79
  80        /*
  81         * Build-time sanity checks on the kernel image and module
  82         * area mappings. (these are purely build-time and produce no code)
  83         */
  84        BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
  85        BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
  86        BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
  87        BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
  88        BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
  89        BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
  90        BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
  91                                (__START_KERNEL & PGDIR_MASK)));
  92        BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
  93
  94        /* clear bss before set_intr_gate with early_idt_handler */
  95        clear_bss();
  96
  97        /* Make NULL pointers segfault */
  98        zap_identity_mappings();
  99
 100        /* Cleanup the over mapped high alias */
 101        cleanup_highmap();
 102
 103        for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
 104#ifdef CONFIG_EARLY_PRINTK
 105                set_intr_gate(i, &early_idt_handlers[i]);
 106#else
 107                set_intr_gate(i, early_idt_handler);
 108#endif
 109        }
 110        load_idt((const struct desc_ptr *)&idt_descr);
 111
 112        if (console_loglevel == 10)
 113                early_printk("Kernel alive\n");
 114
 115        x86_64_init_pda();
 116
 117        x86_64_start_reservations(real_mode_data);
 118}
 119
 120void __init x86_64_start_reservations(char *real_mode_data)
 121{
 122        copy_bootdata(__va(real_mode_data));
 123
 124        reserve_trampoline_memory();
 125
 126        reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
 127
 128#ifdef CONFIG_BLK_DEV_INITRD
 129        /* Reserve INITRD */
 130        if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
 131                unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
 132                unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
 133                unsigned long ramdisk_end   = ramdisk_image + ramdisk_size;
 134                reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
 135        }
 136#endif
 137
 138        reserve_ebda_region();
 139
 140        /*
 141         * At this point everything still needed from the boot loader
 142         * or BIOS or kernel text should be early reserved or marked not
 143         * RAM in e820. All other memory is free game.
 144         */
 145
 146        start_kernel();
 147}
 148
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