setup.c

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/*
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *
 *  Memory region support
 *  David Parsons <[email protected]>, July-August 1999
 *
 *  Added E820 sanitization routine (removes overlapping memory regions);
 *  Brian Moyle <[email protected]>, February 2001
 *
 * Moved CPU detection code to cpu/${cpu}.c
 *    Patrick Mochel <[email protected]>, March 2002
 *
 *  Provisions for empty E820 memory regions (reported by certain BIOSes).
 *  Alex Achenbach <[email protected]>, December 2002.
 *
 */

/*
 * This file handles the architecture-dependent parts of initialization
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/screen_info.h>
#include <linux/ioport.h>
#include <linux/acpi.h>
#include <linux/sfi.h>
#include <linux/apm_bios.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/seq_file.h>
#include <linux/console.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/edd.h>
#include <linux/iscsi_ibft.h>
#include <linux/nodemask.h>
#include <linux/kexec.h>
#include <linux/dmi.h>
#include <linux/pfn.h>
#include <linux/pci.h>
#include <asm/pci-direct.h>
#include <linux/init_ohci1394_dma.h>
#include <linux/kvm_para.h>
#include <linux/dma-contiguous.h>

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/delay.h>

#include <linux/kallsyms.h>
#include <linux/cpufreq.h>
#include <linux/dma-mapping.h>
#include <linux/ctype.h>
#include <linux/uaccess.h>

#include <linux/percpu.h>
#include <linux/crash_dump.h>
#include <linux/tboot.h>
#include <linux/jiffies.h>

#include <video/edid.h>

#include <asm/mtrr.h>
#include <asm/apic.h>
#include <asm/realmode.h>
#include <asm/e820.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
#include <asm/efi.h>
#include <asm/timer.h>
#include <asm/i8259.h>
#include <asm/sections.h>
#include <asm/dmi.h>
#include <asm/io_apic.h>
#include <asm/ist.h>
#include <asm/setup_arch.h>
#include <asm/bios_ebda.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/bugs.h>

#include <asm/vsyscall.h>
#include <asm/cpu.h>
#include <asm/desc.h>
#include <asm/dma.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/mmu_context.h>
#include <asm/proto.h>

#include <asm/paravirt.h>
#include <asm/hypervisor.h>
#include <asm/olpc_ofw.h>

#include <asm/percpu.h>
#include <asm/topology.h>
#include <asm/apicdef.h>
#include <asm/amd_nb.h>
#ifdef CONFIG_X86_64
#include <asm/numa_64.h>
#endif
#include <asm/mce.h>
#include <asm/alternative.h>
#include <asm/prom.h>

/*
 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
 * The direct mapping extends to max_pfn_mapped, so that we can directly access
 * apertures, ACPI and other tables without having to play with fixmaps.
 */
unsigned long max_low_pfn_mapped;
unsigned long max_pfn_mapped;

#ifdef CONFIG_DMI
RESERVE_BRK(dmi_alloc, 65536);
#endif


static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
unsigned long _brk_end = (unsigned long)__brk_base;

#ifdef CONFIG_X86_64
int default_cpu_present_to_apicid(int mps_cpu)
{
    return __default_cpu_present_to_apicid(mps_cpu);
}

int default_check_phys_apicid_present(int phys_apicid)
{
    return __default_check_phys_apicid_present(phys_apicid);
}
#endif

#ifndef CONFIG_DEBUG_BOOT_PARAMS
struct boot_params __initdata boot_params;
#else
struct boot_params boot_params;
#endif

/*
 * Machine setup..
 */
static struct resource data_resource = {
    .name   = "Kernel data",
    .start  = 0,
    .end    = 0,
    .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
};

static struct resource code_resource = {
    .name   = "Kernel code",
    .start  = 0,
    .end    = 0,
    .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
};

static struct resource bss_resource = {
    .name   = "Kernel bss",
    .start  = 0,
    .end    = 0,
    .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
};


#ifdef CONFIG_X86_32
/* cpu data as detected by the assembly code in head.S */
struct cpuinfo_x86 new_cpu_data __cpuinitdata = {0, 0, 0, 0, -1, 1, 0, 0, -1};
/* common cpu data for all cpus */
struct cpuinfo_x86 boot_cpu_data __read_mostly = {0, 0, 0, 0, -1, 1, 0, 0, -1};
EXPORT_SYMBOL(boot_cpu_data);

unsigned int def_to_bigsmp;

/* for MCA, but anyone else can use it if they want */
unsigned int machine_id;
unsigned int machine_submodel_id;
unsigned int BIOS_revision;

struct apm_info apm_info;
EXPORT_SYMBOL(apm_info);

#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
    defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
struct ist_info ist_info;
EXPORT_SYMBOL(ist_info);
#else
struct ist_info ist_info;
#endif

#else
struct cpuinfo_x86 boot_cpu_data __read_mostly = {
    .x86_phys_bits = MAX_PHYSMEM_BITS,
};
EXPORT_SYMBOL(boot_cpu_data);
#endif


#if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
unsigned long mmu_cr4_features;
#else
unsigned long mmu_cr4_features = X86_CR4_PAE;
#endif

/* Boot loader ID and version as integers, for the benefit of proc_dointvec */
int bootloader_type, bootloader_version;

/*
 * Setup options
 */
struct screen_info screen_info;
EXPORT_SYMBOL(screen_info);
struct edid_info edid_info;
EXPORT_SYMBOL_GPL(edid_info);

extern int root_mountflags;

unsigned long saved_video_mode;

#define RAMDISK_IMAGE_START_MASK    0x07FF
#define RAMDISK_PROMPT_FLAG     0x8000
#define RAMDISK_LOAD_FLAG       0x4000

static char __initdata command_line[COMMAND_LINE_SIZE];
#ifdef CONFIG_CMDLINE_BOOL
static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
#endif

#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
struct edd edd;
#ifdef CONFIG_EDD_MODULE
EXPORT_SYMBOL(edd);
#endif

static inline void __init copy_edd(void)
{
     memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
        sizeof(edd.mbr_signature));
     memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
     edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
     edd.edd_info_nr = boot_params.eddbuf_entries;
}
#else
static inline void __init copy_edd(void)
{
}
#endif

void * __init extend_brk(size_t size, size_t align)
{
    size_t mask = align - 1;
    void *ret;

    BUG_ON(_brk_start == 0);
    BUG_ON(align & mask);

    _brk_end = (_brk_end + mask) & ~mask;
    BUG_ON((char *)(_brk_end + size) > __brk_limit);

    ret = (void *)_brk_end;
    _brk_end += size;

    memset(ret, 0, size);

    return ret;
}

#ifdef CONFIG_X86_64
static void __init init_gbpages(void)
{
    if (direct_gbpages && cpu_has_gbpages)
        printk(KERN_INFO "Using GB pages for direct mapping\n");
    else
        direct_gbpages = 0;
}
#else
static inline void init_gbpages(void)
{
}
static void __init cleanup_highmap(void)
{
}
#endif

static void __init reserve_brk(void)
{
    if (_brk_end > _brk_start)
        memblock_reserve(__pa(_brk_start),
                 __pa(_brk_end) - __pa(_brk_start));

    /* Mark brk area as locked down and no longer taking any
       new allocations */
    _brk_start = 0;
}

#ifdef CONFIG_BLK_DEV_INITRD

#define MAX_MAP_CHUNK   (NR_FIX_BTMAPS << PAGE_SHIFT)
static void __init relocate_initrd(void)
{
    /* Assume only end is not page aligned */
    u64 ramdisk_image = boot_params.hdr.ramdisk_image;
    u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
    u64 area_size     = PAGE_ALIGN(ramdisk_size);
    u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;
    u64 ramdisk_here;
    unsigned long slop, clen, mapaddr;
    char *p, *q;

    /* We need to move the initrd down into lowmem */
    ramdisk_here = memblock_find_in_range(0, end_of_lowmem, area_size,
                     PAGE_SIZE);

    if (!ramdisk_here)
        panic("Cannot find place for new RAMDISK of size %lld\n",
             ramdisk_size);

    /* Note: this includes all the lowmem currently occupied by
       the initrd, we rely on that fact to keep the data intact. */
    memblock_reserve(ramdisk_here, area_size);
    initrd_start = ramdisk_here + PAGE_OFFSET;
    initrd_end   = initrd_start + ramdisk_size;
    printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
             ramdisk_here, ramdisk_here + ramdisk_size - 1);

    q = (char *)initrd_start;

    /* Copy any lowmem portion of the initrd */
    if (ramdisk_image < end_of_lowmem) {
        clen = end_of_lowmem - ramdisk_image;
        p = (char *)__va(ramdisk_image);
        memcpy(q, p, clen);
        q += clen;
        ramdisk_image += clen;
        ramdisk_size  -= clen;
    }

    /* Copy the highmem portion of the initrd */
    while (ramdisk_size) {
        slop = ramdisk_image & ~PAGE_MASK;
        clen = ramdisk_size;
        if (clen > MAX_MAP_CHUNK-slop)
            clen = MAX_MAP_CHUNK-slop;
        mapaddr = ramdisk_image & PAGE_MASK;
        p = early_memremap(mapaddr, clen+slop);
        memcpy(q, p+slop, clen);
        early_iounmap(p, clen+slop);
        q += clen;
        ramdisk_image += clen;
        ramdisk_size  -= clen;
    }
    /* high pages is not converted by early_res_to_bootmem */
    ramdisk_image = boot_params.hdr.ramdisk_image;
    ramdisk_size  = boot_params.hdr.ramdisk_size;
    printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
        " [mem %#010llx-%#010llx]\n",
        ramdisk_image, ramdisk_image + ramdisk_size - 1,
        ramdisk_here, ramdisk_here + ramdisk_size - 1);
}

static void __init reserve_initrd(void)
{
    /* Assume only end is not page aligned */
    u64 ramdisk_image = boot_params.hdr.ramdisk_image;
    u64 ramdisk_size  = boot_params.hdr.ramdisk_size;
    u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
    u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;

    if (!boot_params.hdr.type_of_loader ||
        !ramdisk_image || !ramdisk_size)
        return;     /* No initrd provided by bootloader */

    initrd_start = 0;

    if (ramdisk_size >= (end_of_lowmem>>1)) {
        panic("initrd too large to handle, "
               "disabling initrd (%lld needed, %lld available)\n",
               ramdisk_size, end_of_lowmem>>1);
    }

    printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
            ramdisk_end - 1);


    if (ramdisk_end <= end_of_lowmem) {
        /* All in lowmem, easy case */
        /*
         * don't need to reserve again, already reserved early
         * in i386_start_kernel
         */
        initrd_start = ramdisk_image + PAGE_OFFSET;
        initrd_end = initrd_start + ramdisk_size;
        return;
    }

    relocate_initrd();

    memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
}
#else
static void __init reserve_initrd(void)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */

static void __init parse_setup_data(void)
{
    struct setup_data *data;
    u64 pa_data;

    if (boot_params.hdr.version < 0x0209)
        return;
    pa_data = boot_params.hdr.setup_data;
    while (pa_data) {
        u32 data_len, map_len;

        map_len = max(PAGE_SIZE - (pa_data & ~PAGE_MASK),
                  (u64)sizeof(struct setup_data));
        data = early_memremap(pa_data, map_len);
        data_len = data->len + sizeof(struct setup_data);
        if (data_len > map_len) {
            early_iounmap(data, map_len);
            data = early_memremap(pa_data, data_len);
            map_len = data_len;
        }

        switch (data->type) {
        case SETUP_E820_EXT:
            parse_e820_ext(data);
            break;
        case SETUP_DTB:
            add_dtb(pa_data);
            break;
        default:
            break;
        }
        pa_data = data->next;
        early_iounmap(data, map_len);
    }
}

static void __init e820_reserve_setup_data(void)
{
    struct setup_data *data;
    u64 pa_data;
    int found = 0;

    if (boot_params.hdr.version < 0x0209)
        return;
    pa_data = boot_params.hdr.setup_data;
    while (pa_data) {
        data = early_memremap(pa_data, sizeof(*data));
        e820_update_range(pa_data, sizeof(*data)+data->len,
             E820_RAM, E820_RESERVED_KERN);
        found = 1;
        pa_data = data->next;
        early_iounmap(data, sizeof(*data));
    }
    if (!found)
        return;

    sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
    memcpy(&e820_saved, &e820, sizeof(struct e820map));
    printk(KERN_INFO "extended physical RAM map:\n");
    e820_print_map("reserve setup_data");
}

static void __init memblock_x86_reserve_range_setup_data(void)
{
    struct setup_data *data;
    u64 pa_data;

    if (boot_params.hdr.version < 0x0209)
        return;
    pa_data = boot_params.hdr.setup_data;
    while (pa_data) {
        data = early_memremap(pa_data, sizeof(*data));
        memblock_reserve(pa_data, sizeof(*data) + data->len);
        pa_data = data->next;
        early_iounmap(data, sizeof(*data));
    }
}

/*
 * --------- Crashkernel reservation ------------------------------
 */

#ifdef CONFIG_KEXEC

/*
 * Keep the crash kernel below this limit.  On 32 bits earlier kernels
 * would limit the kernel to the low 512 MiB due to mapping restrictions.
 * On 64 bits, kexec-tools currently limits us to 896 MiB; increase this
 * limit once kexec-tools are fixed.
 */
#ifdef CONFIG_X86_32
# define CRASH_KERNEL_ADDR_MAX  (512 << 20)
#else
# define CRASH_KERNEL_ADDR_MAX  (896 << 20)
#endif

static void __init reserve_crashkernel(void)
{
    unsigned long long total_mem;
    unsigned long long crash_size, crash_base;
    int ret;

    total_mem = memblock_phys_mem_size();

    ret = parse_crashkernel(boot_command_line, total_mem,
            &crash_size, &crash_base);
    if (ret != 0 || crash_size <= 0)
        return;

    /* 0 means: find the address automatically */
    if (crash_base <= 0) {
        const unsigned long long alignment = 16<<20;    /* 16M */

        /*
         *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
         */
        crash_base = memblock_find_in_range(alignment,
                   CRASH_KERNEL_ADDR_MAX, crash_size, alignment);

        if (!crash_base) {
            pr_info("crashkernel reservation failed - No suitable area found.\n");
            return;
        }
    } else {
        unsigned long long start;

        start = memblock_find_in_range(crash_base,
                 crash_base + crash_size, crash_size, 1<<20);
        if (start != crash_base) {
            pr_info("crashkernel reservation failed - memory is in use.\n");
            return;
        }
    }
    memblock_reserve(crash_base, crash_size);

    printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
            "for crashkernel (System RAM: %ldMB)\n",
            (unsigned long)(crash_size >> 20),
            (unsigned long)(crash_base >> 20),
            (unsigned long)(total_mem >> 20));

    crashk_res.start = crash_base;
    crashk_res.end   = crash_base + crash_size - 1;
    insert_resource(&iomem_resource, &crashk_res);
}
#else
static void __init reserve_crashkernel(void)
{
}
#endif

static struct resource standard_io_resources[] = {
    { .name = "dma1", .start = 0x00, .end = 0x1f,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "pic1", .start = 0x20, .end = 0x21,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "timer0", .start = 0x40, .end = 0x43,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "timer1", .start = 0x50, .end = 0x53,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "keyboard", .start = 0x60, .end = 0x60,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "keyboard", .start = 0x64, .end = 0x64,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "dma page reg", .start = 0x80, .end = 0x8f,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "pic2", .start = 0xa0, .end = 0xa1,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "dma2", .start = 0xc0, .end = 0xdf,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO },
    { .name = "fpu", .start = 0xf0, .end = 0xff,
        .flags = IORESOURCE_BUSY | IORESOURCE_IO }
};

void __init reserve_standard_io_resources(void)
{
    int i;

    /* request I/O space for devices used on all i[345]86 PCs */
    for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
        request_resource(&ioport_resource, &standard_io_resources[i]);

}

static __init void reserve_ibft_region(void)
{
    unsigned long addr, size = 0;

    addr = find_ibft_region(&size);

    if (size)
        memblock_reserve(addr, size);
}

static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;

static void __init trim_bios_range(void)
{
    /*
     * A special case is the first 4Kb of memory;
     * This is a BIOS owned area, not kernel ram, but generally
     * not listed as such in the E820 table.
     *
     * This typically reserves additional memory (64KiB by default)
     * since some BIOSes are known to corrupt low memory.  See the
     * Kconfig help text for X86_RESERVE_LOW.
     */
    e820_update_range(0, ALIGN(reserve_low, PAGE_SIZE),
              E820_RAM, E820_RESERVED);

    /*
     * special case: Some BIOSen report the PC BIOS
     * area (640->1Mb) as ram even though it is not.
     * take them out.
     */
    e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1);
    sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
}

static int __init parse_reservelow(char *p)
{
    unsigned long long size;

    if (!p)
        return -EINVAL;

    size = memparse(p, &p);

    if (size < 4096)
        size = 4096;

    if (size > 640*1024)
        size = 640*1024;

    reserve_low = size;

    return 0;
}

early_param("reservelow", parse_reservelow);

/*
 * Determine if we were loaded by an EFI loader.  If so, then we have also been
 * passed the efi memmap, systab, etc., so we should use these data structures
 * for initialization.  Note, the efi init code path is determined by the
 * global efi_enabled. This allows the same kernel image to be used on existing
 * systems (with a traditional BIOS) as well as on EFI systems.
 */
/*
 * setup_arch - architecture-specific boot-time initializations
 *
 * Note: On x86_64, fixmaps are ready for use even before this is called.
 */

void __init setup_arch(char **cmdline_p)
{
#ifdef CONFIG_X86_32
    memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
    visws_early_detect();

    /*
     * copy kernel address range established so far and switch
     * to the proper swapper page table
     */
    clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
            initial_page_table + KERNEL_PGD_BOUNDARY,
            KERNEL_PGD_PTRS);

    load_cr3(swapper_pg_dir);
    __flush_tlb_all();
#else
    printk(KERN_INFO "Command line: %s\n", boot_command_line);
#endif

    /*
     * If we have OLPC OFW, we might end up relocating the fixmap due to
     * reserve_top(), so do this before touching the ioremap area.
     */
    olpc_ofw_detect();

    early_trap_init();
    early_cpu_init();
    early_ioremap_init();

    setup_olpc_ofw_pgd();

    ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
    screen_info = boot_params.screen_info;
    edid_info = boot_params.edid_info;
#ifdef CONFIG_X86_32
    apm_info.bios = boot_params.apm_bios_info;
    ist_info = boot_params.ist_info;
    if (boot_params.sys_desc_table.length != 0) {
        machine_id = boot_params.sys_desc_table.table[0];
        machine_submodel_id = boot_params.sys_desc_table.table[1];
        BIOS_revision = boot_params.sys_desc_table.table[2];
    }
#endif
    saved_video_mode = boot_params.hdr.vid_mode;
    bootloader_type = boot_params.hdr.type_of_loader;
    if ((bootloader_type >> 4) == 0xe) {
        bootloader_type &= 0xf;
        bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
    }
    bootloader_version  = bootloader_type & 0xf;
    bootloader_version |= boot_params.hdr.ext_loader_ver << 4;

#ifdef CONFIG_BLK_DEV_RAM
    rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
    rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
    rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
#endif
#ifdef CONFIG_EFI
    if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
             "EL32", 4)) {
        efi_enabled = 1;
        efi_64bit = false;
    } else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
             "EL64", 4)) {
        efi_enabled = 1;
        efi_64bit = true;
    }
    if (efi_enabled && efi_memblock_x86_reserve_range())
        efi_enabled = 0;
#endif

    x86_init.oem.arch_setup();

    iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
    setup_memory_map();
    parse_setup_data();
    /* update the e820_saved too */
    e820_reserve_setup_data();

    copy_edd();

    if (!boot_params.hdr.root_flags)
        root_mountflags &= ~MS_RDONLY;
    init_mm.start_code = (unsigned long) _text;
    init_mm.end_code = (unsigned long) _etext;
    init_mm.end_data = (unsigned long) _edata;
    init_mm.brk = _brk_end;

    code_resource.start = virt_to_phys(_text);
    code_resource.end = virt_to_phys(_etext)-1;
    data_resource.start = virt_to_phys(_etext);
    data_resource.end = virt_to_phys(_edata)-1;
    bss_resource.start = virt_to_phys(&__bss_start);
    bss_resource.end = virt_to_phys(&__bss_stop)-1;

#ifdef CONFIG_CMDLINE_BOOL
#ifdef CONFIG_CMDLINE_OVERRIDE
    strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
    if (builtin_cmdline[0]) {
        /* append boot loader cmdline to builtin */
        strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
        strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
        strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
    }
#endif
#endif

    strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
    *cmdline_p = command_line;

    /*
     * x86_configure_nx() is called before parse_early_param() to detect
     * whether hardware doesn't support NX (so that the early EHCI debug
     * console setup can safely call set_fixmap()). It may then be called
     * again from within noexec_setup() during parsing early parameters
     * to honor the respective command line option.
     */
    x86_configure_nx();

    parse_early_param();

    x86_report_nx();

    /* after early param, so could get panic from serial */
    memblock_x86_reserve_range_setup_data();

    if (acpi_mps_check()) {
#ifdef CONFIG_X86_LOCAL_APIC
        disable_apic = 1;
#endif
        setup_clear_cpu_cap(X86_FEATURE_APIC);
    }

#ifdef CONFIG_PCI
    if (pci_early_dump_regs)
        early_dump_pci_devices();
#endif

    finish_e820_parsing();

    if (efi_enabled)
        efi_init();

    dmi_scan_machine();

    /*
     * VMware detection requires dmi to be available, so this
     * needs to be done after dmi_scan_machine, for the BP.
     */
    init_hypervisor_platform();

    x86_init.resources.probe_roms();

    /* after parse_early_param, so could debug it */
    insert_resource(&iomem_resource, &code_resource);
    insert_resource(&iomem_resource, &data_resource);
    insert_resource(&iomem_resource, &bss_resource);

    trim_bios_range();
#ifdef CONFIG_X86_32
    if (ppro_with_ram_bug()) {
        e820_update_range(0x70000000ULL, 0x40000ULL, E820_RAM,
                  E820_RESERVED);
        sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
        printk(KERN_INFO "fixed physical RAM map:\n");
        e820_print_map("bad_ppro");
    }
#else
    early_gart_iommu_check();
#endif

    /*
     * partially used pages are not usable - thus
     * we are rounding upwards:
     */
    max_pfn = e820_end_of_ram_pfn();

    /* update e820 for memory not covered by WB MTRRs */
    mtrr_bp_init();
    if (mtrr_trim_uncached_memory(max_pfn))
        max_pfn = e820_end_of_ram_pfn();

#ifdef CONFIG_X86_32
    /* max_low_pfn get updated here */
    find_low_pfn_range();
#else
    num_physpages = max_pfn;

    check_x2apic();

    /* How many end-of-memory variables you have, grandma! */
    /* need this before calling reserve_initrd */
    if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
        max_low_pfn = e820_end_of_low_ram_pfn();
    else
        max_low_pfn = max_pfn;

    high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
#endif

    /*
     * Find and reserve possible boot-time SMP configuration:
     */
    find_smp_config();

    reserve_ibft_region();

    /*
     * Need to conclude brk, before memblock_x86_fill()
     *  it could use memblock_find_in_range, could overlap with
     *  brk area.
     */
    reserve_brk();

    cleanup_highmap();

    memblock.current_limit = get_max_mapped();
    memblock_x86_fill();

    /*
     * The EFI specification says that boot service code won't be called
     * after ExitBootServices(). This is, in fact, a lie.
     */
    if (efi_enabled)
        efi_reserve_boot_services();

    /* preallocate 4k for mptable mpc */
    early_reserve_e820_mpc_new();

#ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
    setup_bios_corruption_check();
#endif

    printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
            (max_pfn_mapped<<PAGE_SHIFT) - 1);

    setup_real_mode();

    init_gbpages();

    /* max_pfn_mapped is updated here */
    max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
    max_pfn_mapped = max_low_pfn_mapped;

#ifdef CONFIG_X86_64
    if (max_pfn > max_low_pfn) {
        int i;
        unsigned long start, end;
        unsigned long start_pfn, end_pfn;

        for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn,
                             NULL) {

            end = PFN_PHYS(end_pfn);
            if (end <= (1UL<<32))
                continue;

            start = PFN_PHYS(start_pfn);
            max_pfn_mapped = init_memory_mapping(
                        max((1UL<<32), start), end);
        }

        /* can we preseve max_low_pfn ?*/
        max_low_pfn = max_pfn;
    }
#endif
    memblock.current_limit = get_max_mapped();
    dma_contiguous_reserve(0);

    /*
     * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
     */

#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
    if (init_ohci1394_dma_early)
        init_ohci1394_dma_on_all_controllers();
#endif
    /* Allocate bigger log buffer */
    setup_log_buf(1);

    reserve_initrd();

    reserve_crashkernel();

    vsmp_init();

    io_delay_init();

    /*
     * Parse the ACPI tables for possible boot-time SMP configuration.
     */
    acpi_boot_table_init();

    early_acpi_boot_init();

    initmem_init();
    memblock_find_dma_reserve();

#ifdef CONFIG_KVM_GUEST
    kvmclock_init();
#endif

    x86_init.paging.pagetable_init();

    if (boot_cpu_data.cpuid_level >= 0) {
        /* A CPU has %cr4 if and only if it has CPUID */
        mmu_cr4_features = read_cr4();
        if (trampoline_cr4_features)
            *trampoline_cr4_features = mmu_cr4_features;
    }

#ifdef CONFIG_X86_32
    /* sync back kernel address range */
    clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
            swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
            KERNEL_PGD_PTRS);
#endif

    tboot_probe();

#ifdef CONFIG_X86_64
    map_vsyscall();
#endif

    generic_apic_probe();

    early_quirks();

    /*
     * Read APIC and some other early information from ACPI tables.
     */
    acpi_boot_init();
    sfi_init();
    x86_dtb_init();

    /*
     * get boot-time SMP configuration:
     */
    if (smp_found_config)
        get_smp_config();

    prefill_possible_map();

    init_cpu_to_node();

    init_apic_mappings();
    if (x86_io_apic_ops.init)
        x86_io_apic_ops.init();

    kvm_guest_init();

    e820_reserve_resources();
    e820_mark_nosave_regions(max_low_pfn);

    x86_init.resources.reserve_resources();

    e820_setup_gap();

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
    if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
        conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
    conswitchp = &dummy_con;
#endif
#endif
    x86_init.oem.banner();

    x86_init.timers.wallclock_init();

    mcheck_init();

    arch_init_ideal_nops();

    register_refined_jiffies(CLOCK_TICK_RATE);

#ifdef CONFIG_EFI
    /* Once setup is done above, disable efi_enabled on mismatched
     * firmware/kernel archtectures since there is no support for
     * runtime services.
     */
    if (efi_enabled && IS_ENABLED(CONFIG_X86_64) != efi_64bit) {
        pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
        efi_unmap_memmap();
        efi_enabled = 0;
    }
#endif
}

#ifdef CONFIG_X86_32

static struct resource video_ram_resource = {
    .name   = "Video RAM area",
    .start  = 0xa0000,
    .end    = 0xbffff,
    .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
};

void __init i386_reserve_resources(void)
{
    request_resource(&iomem_resource, &video_ram_resource);
    reserve_standard_io_resources();
}

#endif /* CONFIG_X86_32 */