/OpenKeychain/src/main/res/

#include <xen/config.h>
#include <xen/init.h>
#include <xen/lib.h>
#include <xen/err.h>
#include <xen/sched.h>
#include <xen/sched-if.h>
#include <xen/domain.h>
#include <xen/serial.h>
#include <xen/softirq.h>
#include <xen/acpi.h>
#include <xen/console.h>
#include <xen/serial.h>
#include <xen/trace.h>
#include <xen/multiboot.h>
#include <xen/domain_page.h>
#include <xen/version.h>
#include <xen/gdbstub.h>
#include <xen/percpu.h>
#include <xen/hypercall.h>
#include <xen/keyhandler.h>
#include <xen/numa.h>
#include <xen/rcupdate.h>
#include <xen/vga.h>
#include <xen/dmi.h>
#include <xen/nodemask.h>
#include <public/version.h>
#ifdef CONFIG_COMPAT
#include <compat/platform.h>
#include <compat/xen.h>
#endif
#include <asm/bitops.h>
#include <asm/smp.h>
#include <asm/processor.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <asm/desc.h>
#include <asm/paging.h>
#include <asm/e820.h>
#include <xsm/acm/acm_hooks.h>
#include <xen/kexec.h>
#include <asm/edd.h>
#include <xsm/xsm.h>
#include <asm/tboot.h>
#include <asm/bzimage.h> /* for bzimage_headroom */
#include <asm/mach-generic/mach_apic.h> /* for generic_apic_probe */
#include <asm/setup.h>
#include <xen/cpu.h>

extern u16 boot_edid_caps;
extern u8 boot_edid_info[128];
extern struct boot_video_info boot_vid_info;

/* opt_nosmp: If true, secondary processors are ignored. */
static bool_t __initdata opt_nosmp;
boolean_param("nosmp", opt_nosmp);

/* maxcpus: maximum number of CPUs to activate. */
static unsigned int __initdata max_cpus = NR_CPUS;
integer_param("maxcpus", max_cpus);

/* opt_watchdog: If true, run a watchdog NMI on each processor. */
static bool_t __initdata opt_watchdog;
boolean_param("watchdog", opt_watchdog);

/* smep: Enable/disable Supervisor Mode Execution Protection (default on). */
static bool_t __initdata disable_smep;
invbool_param("smep", disable_smep);

/* **** Linux config option: propagated to domain0. */
/* "acpi=off":    Sisables both ACPI table parsing and interpreter. */
/* "acpi=force":  Override the disable blacklist.                   */
/* "acpi=strict": Disables out-of-spec workarounds.                 */
/* "acpi=ht":     Limit ACPI just to boot-time to enable HT.        */
/* "acpi=noirq":  Disables ACPI interrupt routing.                  */
static void parse_acpi_param(char *s);
custom_param("acpi", parse_acpi_param);

/* **** Linux config option: propagated to domain0. */
/* acpi_skip_timer_override: Skip IRQ0 overrides. */
boolean_param("acpi_skip_timer_override", acpi_skip_timer_override);

/* **** Linux config option: propagated to domain0. */
/* noapic: Disable IOAPIC setup. */
boolean_param("noapic", skip_ioapic_setup);

/* **** Linux config option: propagated to domain0. */
/* xen_cpuidle: xen control cstate. */
s8 __read_mostly xen_cpuidle = -1;
boolean_param("cpuidle", xen_cpuidle);

cpumask_t __read_mostly cpu_present_map;

unsigned long __read_mostly xen_phys_start;

#ifdef CONFIG_X86_32
/* Limits of Xen heap, used to initialise the allocator. */
unsigned long __initdata xenheap_initial_phys_start;
unsigned long __read_mostly xenheap_phys_end;
#endif

DEFINE_PER_CPU(struct tss_struct, init_tss);

char __attribute__ ((__section__(".bss.stack_aligned"))) cpu0_stack[STACK_SIZE];

struct cpuinfo_x86 __read_mostly boot_cpu_data = { 0, 0, 0, 0, -1 };

unsigned long __read_mostly mmu_cr4_features = X86_CR4_PSE | X86_CR4_PGE | X86_CR4_PAE;

bool_t __initdata acpi_disabled;
bool_t __initdata acpi_force;
static char __initdata acpi_param[10] = "";
static void __init parse_acpi_param(char *s)
{
    /* Save the parameter so it can be propagated to domain0. */
    safe_strcpy(acpi_param, s);

    /* Interpret the parameter for use within Xen. */
    if ( !parse_bool(s) )
    {
        disable_acpi();
    }
    else if ( !strcmp(s, "force") )
    {
        acpi_force = 1;
        acpi_ht = 1;
        acpi_disabled = 0;
    }
    else if ( !strcmp(s, "ht") )
    {
        if ( !acpi_force )
            disable_acpi();
        acpi_ht = 1;
    }
    else if ( !strcmp(s, "noirq") )
    {
        acpi_noirq_set();
    }
}

#define EARLY_FAIL(f, a...) do {                \
    printk( f , ## a );                         \
    for ( ; ; ) halt();                         \
} while (0)

static const module_t *__initdata initial_images;
static unsigned int __initdata nr_initial_images;

unsigned long __init initial_images_nrpages(void)
{
    unsigned long nr;
    unsigned int i;

    for ( nr = i = 0; i < nr_initial_images; ++i )
        nr += PFN_UP(initial_images[i].mod_end);

    return nr;
}

void __init discard_initial_images(void)
{
    unsigned int i;

    for ( i = 0; i < nr_initial_images; ++i )
    {
        uint64_t start = (uint64_t)initial_images[i].mod_start << PAGE_SHIFT;

        init_domheap_pages(start,
                           start + PAGE_ALIGN(initial_images[i].mod_end));
    }

    nr_initial_images = 0;
    initial_images = NULL;
}

static void free_xen_data(char *s, char *e)
{
#ifndef MEMORY_GUARD
    init_xenheap_pages(__pa(s), __pa(e));
#endif
    memguard_guard_range(s, e-s);
#if defined(CONFIG_X86_64)
    /* Also zap the mapping in the 1:1 area. */
    memguard_guard_range(__va(__pa(s)), e-s);
#endif
}

extern char __init_begin[], __init_end[], __bss_start[];

static void __init init_idle_domain(void)
{
    scheduler_init();
    set_current(idle_vcpu[0]);
    this_cpu(curr_vcpu) = current;
    setup_idle_pagetable();
}

void __devinit srat_detect_node(int cpu)
{
    unsigned node;
    u32 apicid = x86_cpu_to_apicid[cpu];

    node = apicid_to_node[apicid];
    if ( node == NUMA_NO_NODE || !node_online(node) )
        node = 0;
    numa_set_node(cpu, node);

    if ( opt_cpu_info && acpi_numa > 0 )
        printk("CPU %d APIC %d -> Node %d\n", cpu, apicid, node);
}

/*
 * Sort CPUs by <node,package,core,thread> tuple. Fortunately this hierarchy is
 * reflected in the structure of modern APIC identifiers, so we sort based on
 * those. This is slightly complicated by the fact that the BSP must remain
 * CPU 0. Hence we do a variation on longest-prefix matching to do the best we
 * can while keeping CPU 0 static.
 */
static void __init normalise_cpu_order(void)
{
    unsigned int i, j, min_cpu;
    uint32_t apicid, diff, min_diff;

    for_each_present_cpu ( i )
    {
        apicid = x86_cpu_to_apicid[i];
        min_diff = min_cpu = ~0u;

        /*
         * Find remaining CPU with longest-prefix match on APIC ID.
         * Among identical longest-prefix matches, pick the smallest APIC ID.
         */
        for ( j = next_cpu(i, cpu_present_map);
              j < NR_CPUS;
              j = next_cpu(j, cpu_present_map) )
        {
            diff = x86_cpu_to_apicid[j] ^ apicid;
            while ( diff & (diff-1) )
                diff &= diff-1;
            if ( (diff < min_diff) ||
                 ((diff == min_diff) &&
                  (x86_cpu_to_apicid[j] < x86_cpu_to_apicid[min_cpu])) )
            {
                min_diff = diff;
                min_cpu = j;
            }
        }

        /* If no match then there must be no CPUs remaining to consider. */
        if ( min_cpu >= NR_CPUS )
        {
            BUG_ON(next_cpu(i, cpu_present_map) < NR_CPUS);
            break;
        }

        /* Switch the best-matching CPU with the next CPU in logical order. */
        j = next_cpu(i, cpu_present_map);
        apicid = x86_cpu_to_apicid[min_cpu];
        x86_cpu_to_apicid[min_cpu] = x86_cpu_to_apicid[j];
        x86_cpu_to_apicid[j] = apicid;
    }
}

#define BOOTSTRAP_MAP_BASE  (16UL << 20)
#define BOOTSTRAP_MAP_LIMIT (1UL << L3_PAGETABLE_SHIFT)

/*
 * Ensure a given physical memory range is present in the bootstrap mappings.
 * Use superpage mappings to ensure that pagetable memory needn't be allocated.
 */
static void *__init bootstrap_map(const module_t *mod)
{
    static unsigned long __initdata map_cur = BOOTSTRAP_MAP_BASE;
    uint64_t start, end, mask = (1L << L2_PAGETABLE_SHIFT) - 1;
    void *ret;

#ifdef __x86_64__
    if ( system_state != SYS_STATE_early_boot )
        return mod ? mfn_to_virt(mod->mod_start) : NULL;
#endif

    if ( !mod )
    {
        destroy_xen_mappings(BOOTSTRAP_MAP_BASE, BOOTSTRAP_MAP_LIMIT);
        map_cur = BOOTSTRAP_MAP_BASE;
        return NULL;
    }

    start = (uint64_t)mod->mod_start << PAGE_SHIFT;
    end = start + mod->mod_end;
    if ( start >= end )
        return NULL;

    if ( end <= BOOTSTRAP_MAP_BASE )
        return (void *)(unsigned long)start;

    ret = (void *)(map_cur + (unsigned long)(start & mask));
    start &= ~mask;
    end = (end + mask) & ~mask;
    if ( end - start > BOOTSTRAP_MAP_LIMIT - map_cur )
        return NULL;

    map_pages_to_xen(map_cur, start >> PAGE_SHIFT,
                     (end - start) >> PAGE_SHIFT, PAGE_HYPERVISOR);
    map_cur += end - start;
    return ret;
}

static void *__init move_memory(
    uint64_t dst, uint64_t src, unsigned int size, bool_t keep)
{
    unsigned int blksz = BOOTSTRAP_MAP_LIMIT - BOOTSTRAP_MAP_BASE;
    unsigned int mask = (1L << L2_PAGETABLE_SHIFT) - 1;

    if ( src + size > BOOTSTRAP_MAP_BASE )
        blksz >>= 1;

    while ( size )
    {
        module_t mod;
        unsigned int soffs = src & mask;
        unsigned int doffs = dst & mask;
        unsigned int sz;
        void *d, *s;

        mod.mod_start = (src - soffs) >> PAGE_SHIFT;
        mod.mod_end = soffs + size;
        if ( mod.mod_end > blksz )
            mod.mod_end = blksz;
        sz = mod.mod_end - soffs;
        s = bootstrap_map(&mod);

        mod.mod_start = (dst - doffs) >> PAGE_SHIFT;
        mod.mod_end = doffs + size;
        if ( mod.mod_end > blksz )
            mod.mod_end = blksz;
        if ( sz > mod.mod_end - doffs )
            sz = mod.mod_end - doffs;
        d = bootstrap_map(&mod);

        memmove(d + doffs, s + soffs, sz);

        dst += sz;
        src += sz;
        size -= sz;

        if ( keep )
            return size ? NULL : d + doffs;

        bootstrap_map(NULL);
    }

    return NULL;
}

static uint64_t __init consider_modules(
    uint64_t s, uint64_t e, uint32_t size, const module_t *mod,
    unsigned int nr_mods, unsigned int this_mod)
{
    unsigned int i;

    if ( s > e || e - s < size )
        return 0;

    for ( i = 0; i < nr_mods ; ++i )
    {
        uint64_t start = (uint64_t)mod[i].mod_start << PAGE_SHIFT;
        uint64_t end = start + PAGE_ALIGN(mod[i].mod_end);

        if ( i == this_mod )
            continue;

        if ( s < end && start < e )
        {
            end = consider_modules(end, e, size, mod + i + 1,
                                   nr_mods - i - 1, this_mod - i - 1);
            if ( end )
                return end;

            return consider_modules(s, start, size, mod + i + 1,
                                    nr_mods - i - 1, this_mod - i - 1);
        }
    }

    return e;
}

static void __init setup_max_pdx(void)
{
#ifdef __x86_64__
    max_pdx = pfn_to_pdx(max_page - 1) + 1;

    if ( max_pdx > (DIRECTMAP_SIZE >> PAGE_SHIFT) )
        max_pdx = DIRECTMAP_SIZE >> PAGE_SHIFT;

    if ( max_pdx > FRAMETABLE_SIZE / sizeof(*frame_table) )
        max_pdx = FRAMETABLE_SIZE / sizeof(*frame_table);

    max_page = pdx_to_pfn(max_pdx - 1) + 1;
#endif
}

void set_pdx_range(unsigned long smfn, unsigned long emfn)
{
    unsigned long idx, eidx;

    idx = pfn_to_pdx(smfn) / PDX_GROUP_COUNT;
    eidx = (pfn_to_pdx(emfn - 1) + PDX_GROUP_COUNT) / PDX_GROUP_COUNT;
    for ( ; idx < eidx; ++idx )
        __set_bit(idx, pdx_group_valid);
}

/* A temporary copy of the e820 map that we can mess with during bootstrap. */
static struct e820map __initdata boot_e820;

struct boot_video_info {
    u8  orig_x;             /* 0x00 */
    u8  orig_y;             /* 0x01 */
    u8  orig_video_mode;    /* 0x02 */
    u8  orig_video_cols;    /* 0x03 */
    u8  orig_video_lines;   /* 0x04 */
    u8  orig_video_isVGA;   /* 0x05 */
    u16 orig_video_points;  /* 0x06 */

    /* VESA graphic mode -- linear frame buffer */
    u32 capabilities;       /* 0x08 */
    u16 lfb_linelength;     /* 0x0c */
    u16 lfb_width;          /* 0x0e */
    u16 lfb_height;         /* 0x10 */
    u16 lfb_depth;          /* 0x12 */
    u32 lfb_base;           /* 0x14 */
    u32 lfb_size;           /* 0x18 */
    u8  red_size;           /* 0x1c */
    u8  red_pos;            /* 0x1d */
    u8  green_size;         /* 0x1e */
    u8  green_pos;          /* 0x1f */
    u8  blue_size;          /* 0x20 */
    u8  blue_pos;           /* 0x21 */
    u8  rsvd_size;          /* 0x22 */
    u8  rsvd_pos;           /* 0x23 */
    u16 vesapm_seg;         /* 0x24 */
    u16 vesapm_off;         /* 0x26 */
    u16 vesa_attrib;        /* 0x28 */
};

static void __init parse_video_info(void)
{
    struct boot_video_info *bvi = &bootsym(boot_vid_info);

    if ( (bvi->orig_video_isVGA == 1) && (bvi->orig_video_mode == 3) )
    {
        vga_console_info.video_type = XEN_VGATYPE_TEXT_MODE_3;
        vga_console_info.u.text_mode_3.font_height = bvi->orig_video_points;
        vga_console_info.u.text_mode_3.cursor_x = bvi->orig_x;
        vga_console_info.u.text_mode_3.cursor_y = bvi->orig_y;
        vga_console_info.u.text_mode_3.rows = bvi->orig_video_lines;
        vga_console_info.u.text_mode_3.columns = bvi->orig_video_cols;
    }
    else if ( bvi->orig_video_isVGA == 0x23 )
    {
        vga_console_info.video_type = XEN_VGATYPE_VESA_LFB;
        vga_console_info.u.vesa_lfb.width = bvi->lfb_width;
        vga_console_info.u.vesa_lfb.height = bvi->lfb_height;
        vga_console_info.u.vesa_lfb.bytes_per_line = bvi->lfb_linelength;
        vga_console_info.u.vesa_lfb.bits_per_pixel = bvi->lfb_depth;
        vga_console_info.u.vesa_lfb.lfb_base = bvi->lfb_base;
        vga_console_info.u.vesa_lfb.lfb_size = bvi->lfb_size;
        vga_console_info.u.vesa_lfb.red_pos = bvi->red_pos;
        vga_console_info.u.vesa_lfb.red_size = bvi->red_size;
        vga_console_info.u.vesa_lfb.green_pos = bvi->green_pos;
        vga_console_info.u.vesa_lfb.green_size = bvi->green_size;
        vga_console_info.u.vesa_lfb.blue_pos = bvi->blue_pos;
        vga_console_info.u.vesa_lfb.blue_size = bvi->blue_size;
        vga_console_info.u.vesa_lfb.rsvd_pos = bvi->rsvd_pos;
        vga_console_info.u.vesa_lfb.rsvd_size = bvi->rsvd_size;
        vga_console_info.u.vesa_lfb.gbl_caps = bvi->capabilities;
        vga_console_info.u.vesa_lfb.mode_attrs = bvi->vesa_attrib;
    }
}

static void __init kexec_reserve_area(struct e820map *e820)
{
    unsigned long kdump_start = kexec_crash_area.start;
    unsigned long kdump_size  = kexec_crash_area.size;
    static int is_reserved = 0;

    kdump_size = (kdump_size + PAGE_SIZE - 1) & PAGE_MASK;

    if ( (kdump_start == 0) || (kdump_size == 0) || is_reserved )
        return;

    is_reserved = 1;

    if ( !reserve_e820_ram(e820, kdump_start, kdump_start + kdump_size) )
    {
        printk("Kdump: DISABLED (failed to reserve %luMB (%lukB) at 0x%lx)"
               "\n", kdump_size >> 20, kdump_size >> 10, kdump_start);
        kexec_crash_area.start = kexec_crash_area.size = 0;
    }
    else
    {
        printk("Kdump: %luMB (%lukB) at 0x%lx\n",
               kdump_size >> 20, kdump_size >> 10, kdump_start);
    }
}

void init_done(void)
{
    /* Free (or page-protect) the init areas. */
    memset(__init_begin, 0xcc, __init_end - __init_begin); /* int3 poison */
    free_xen_data(__init_begin, __init_end);
    printk("Freed %ldkB init memory.\n", (long)(__init_end-__init_begin)>>10);

    startup_cpu_idle_loop();
}

static bool_t __init loader_is_grub2(const char *loader_name)
{
    /* GRUB1="GNU GRUB 0.xx"; GRUB2="GRUB 1.xx" */
    const char *p = strstr(loader_name, "GRUB ");
    return (p != NULL) && (p[5] != '0');
}

static char * __init cmdline_cook(char *p, char *loader_name)
{
    p = p ? : "";

    /* Strip leading whitespace. */
    while ( *p == ' ' )
        p++;

    /* GRUB2 does not include image name as first item on command line. */
    if ( loader_is_grub2(loader_name) )
        return p;

    /* Strip image name plus whitespace. */
    while ( (*p != ' ') && (*p != '\0') )
        p++;
    while ( *p == ' ' )
        p++;

    return p;
}

void __init __start_xen(unsigned long mbi_p)
{
    char *memmap_type = NULL;
    char *cmdline, *kextra, *loader;
    unsigned int initrdidx = 1;
    multiboot_info_t *mbi = __va(mbi_p);
    module_t *mod = (module_t *)__va(mbi->mods_addr);
    unsigned long nr_pages, modules_headroom;
    int i, j, e820_warn = 0, bytes = 0;
    bool_t acpi_boot_table_init_done = 0;
    struct ns16550_defaults ns16550 = {
        .data_bits = 8,
        .parity    = 'n',
        .stop_bits = 1
    };

    percpu_init_areas();

    set_intr_gate(TRAP_page_fault, &early_page_fault);

    loader = (mbi->flags & MBI_LOADERNAME)
        ? (char *)__va(mbi->boot_loader_name) : "unknown";

    /* Parse the command-line options. */
    cmdline = cmdline_cook((mbi->flags & MBI_CMDLINE) ?
                           __va(mbi->cmdline) : NULL,
                           loader);
    if ( (kextra = strstr(cmdline, " -- ")) != NULL )
    {
        /*
         * Options after ' -- ' separator belong to dom0.
         *  1. Orphan dom0's options from Xen's command line.
         *  2. Skip all but final leading space from dom0's options.
         */
        *kextra = '\0';
        kextra += 3;
        while ( kextra[1] == ' ' ) kextra++;
    }
    cmdline_parse(cmdline);

    parse_video_info();

    set_current((struct vcpu *)0xfffff000); /* debug sanity */
    idle_vcpu[0] = current;
    set_processor_id(0); /* needed early, for smp_processor_id() */
    if ( cpu_has_efer )
        rdmsrl(MSR_EFER, this_cpu(efer));
    asm volatile ( "mov %%cr4,%0" : "=r" (this_cpu(cr4)) );

    smp_prepare_boot_cpu();

    /* We initialise the serial devices very early so we can get debugging. */
    ns16550.io_base = 0x3f8;
    ns16550.irq     = 4;
    ns16550_init(0, &ns16550);
    ns16550.io_base = 0x2f8;
    ns16550.irq     = 3;
    ns16550_init(1, &ns16550);
    console_init_preirq();

    printk("Bootloader: %s\n", loader);

    printk("Command line: %s\n", cmdline);

    printk("Video information:\n");

    /* Print VGA display mode information. */
    switch ( vga_console_info.video_type )
    {
    case XEN_VGATYPE_TEXT_MODE_3:
        printk(" VGA is text mode %dx%d, font 8x%d\n",
               vga_console_info.u.text_mode_3.columns,
               vga_console_info.u.text_mode_3.rows,
               vga_console_info.u.text_mode_3.font_height);
        break;
    case XEN_VGATYPE_VESA_LFB:
        printk(" VGA is graphics mode %dx%d, %d bpp\n",
               vga_console_info.u.vesa_lfb.width,
               vga_console_info.u.vesa_lfb.height,
               vga_console_info.u.vesa_lfb.bits_per_pixel);
        break;
    default:
        printk(" No VGA detected\n");
        break;
    }

    /* Print VBE/DDC EDID information. */
    if ( bootsym(boot_edid_caps) != 0x1313 )
    {
        u16 caps = bootsym(boot_edid_caps);
        printk(" VBE/DDC methods:%s%s%s; ",
               (caps & 1) ? " V1" : "",
               (caps & 2) ? " V2" : "",
               !(caps & 3) ? " none" : "");
        printk("EDID transfer time: %d seconds\n", caps >> 8);
        if ( *(u32 *)bootsym(boot_edid_info) == 0x13131313 )
        {
            printk(" EDID info not retrieved because ");
            if ( !(caps & 3) )
                printk("no DDC retrieval method detected\n");
            else if ( (caps >> 8) > 5 )
                printk("takes longer than 5 seconds\n");
            else
                printk("of reasons unknown\n");
        }
    }

    printk("Disc information:\n");
    printk(" Found %d MBR signatures\n",
           bootsym(boot_mbr_signature_nr));
    printk(" Found %d EDD information structures\n",
           bootsym(boot_edd_info_nr));

    /* Check that we have at least one Multiboot module. */
    if ( !(mbi->flags & MBI_MODULES) || (mbi->mods_count == 0) )
        EARLY_FAIL("dom0 kernel not specified. "
                   "Check bootloader configuration.\n");

    if ( ((unsigned long)cpu0_stack & (STACK_SIZE-1)) != 0 )
        EARLY_FAIL("Misaligned CPU0 stack.\n");

    if ( e820_raw_nr != 0 )
    {
        memmap_type = "Xen-e820";
    }
    else if ( mbi->flags & MBI_MEMMAP )
    {
        memmap_type = "Multiboot-e820";
        while ( (bytes < mbi->mmap_length) && (e820_raw_nr < E820MAX) )
        {
            memory_map_t *map = __va(mbi->mmap_addr + bytes);

            /*
             * This is a gross workaround for a BIOS bug. Some bootloaders do
             * not write e820 map entries into pre-zeroed memory. This is
             * okay if the BIOS fills in all fields of the map entry, but
             * some broken BIOSes do not bother to write the high word of
             * the length field if the length is smaller than 4GB. We
             * detect and fix this by flagging sections below 4GB that
             * appear to be larger than 4GB in size.
             */
            if ( (map->base_addr_high == 0) && (map->length_high != 0) )
            {
                if ( !e820_warn )
                {
                    printk("WARNING: Buggy e820 map detected and fixed "
                           "(truncated length fields).\n");
                    e820_warn = 1;
                }
                map->length_high = 0;
            }

            e820_raw[e820_raw_nr].addr = 
                ((u64)map->base_addr_high << 32) | (u64)map->base_addr_low;
            e820_raw[e820_raw_nr].size = 
                ((u64)map->length_high << 32) | (u64)map->length_low;
            e820_raw[e820_raw_nr].type = map->type;
            e820_raw_nr++;

            bytes += map->size + 4;
        }
    }
    else if ( bootsym(lowmem_kb) )
    {
        memmap_type = "Xen-e801";
        e820_raw[0].addr = 0;
        e820_raw[0].size = bootsym(lowmem_kb) << 10;
        e820_raw[0].type = E820_RAM;
        e820_raw[1].addr = 0x100000;
        e820_raw[1].size = bootsym(highmem_kb) << 10;
        e820_raw[1].type = E820_RAM;
        e820_raw_nr = 2;
    }
    else if ( mbi->flags & MBI_MEMLIMITS )
    {
        memmap_type = "Multiboot-e801";
        e820_raw[0].addr = 0;
        e820_raw[0].size = mbi->mem_lower << 10;
        e820_raw[0].type = E820_RAM;
        e820_raw[1].addr = 0x100000;
        e820_raw[1].size = mbi->mem_upper << 10;
        e820_raw[1].type = E820_RAM;
        e820_raw_nr = 2;
    }
    else
    {
        EARLY_FAIL("Bootloader provided no memory information.\n");
    }

    /* Sanitise the raw E820 map to produce a final clean version. */
    max_page = init_e820(memmap_type, e820_raw, &e820_raw_nr);

    /* Create a temporary copy of the E820 map. */
    memcpy(&boot_e820, &e820, sizeof(e820));

    /* Early kexec reservation (explicit static start address). */
    nr_pages = 0;
    for ( i = 0; i < e820.nr_map; i++ )
        if ( e820.map[i].type == E820_RAM )
            nr_pages += e820.map[i].size >> PAGE_SHIFT;
    set_kexec_crash_area_size((u64)nr_pages << PAGE_SHIFT);
    kexec_reserve_area(&boot_e820);

    initial_images = mod;
    nr_initial_images = mbi->mods_count;

    /*
     * Iterate backwards over all superpage-aligned RAM regions.
     * 
     * We require superpage alignment because the boot allocator is not yet
     * initialised. Hence we can only map superpages in the address range
     * 0 to BOOTSTRAP_DIRECTMAP_END, as this is guaranteed not to require
     * dynamic allocation of pagetables.
     * 
     * As well as mapping superpages in that range, in preparation for
     * initialising the boot allocator, we also look for a region to which
     * we can relocate the dom0 kernel and other multiboot modules. Also, on
     * x86/64, we relocate Xen to higher memory.
     */
    for ( i = 0; i < mbi->mods_count; i++ )
    {
        if ( mod[i].mod_start & (PAGE_SIZE - 1) )
            EARLY_FAIL("Bootloader didn't honor module alignment request.\n");
        mod[i].mod_end -= mod[i].mod_start;
        mod[i].mod_start >>= PAGE_SHIFT;
        mod[i].reserved = 0;
    }

    modules_headroom = bzimage_headroom(bootstrap_map(mod), mod->mod_end);
    bootstrap_map(NULL);

    for ( i = boot_e820.nr_map-1; i >= 0; i-- )
    {
        uint64_t s, e, mask = (1UL << L2_PAGETABLE_SHIFT) - 1;
        uint64_t end, limit = ARRAY_SIZE(l2_identmap) << L2_PAGETABLE_SHIFT;

        /* Superpage-aligned chunks from BOOTSTRAP_MAP_BASE. */
        s = (boot_e820.map[i].addr + mask) & ~mask;
        e = (boot_e820.map[i].addr + boot_e820.map[i].size) & ~mask;
        s = max_t(uint64_t, s, BOOTSTRAP_MAP_BASE);
        if ( (boot_e820.map[i].type != E820_RAM) || (s >= e) )
            continue;

        if ( s < limit )
        {
            end = min(e, limit);
            set_pdx_range(s >> PAGE_SHIFT, end >> PAGE_SHIFT);
#ifdef CONFIG_X86_64
            map_pages_to_xen((unsigned long)__va(s), s >> PAGE_SHIFT,
                             (end - s) >> PAGE_SHIFT, PAGE_HYPERVISOR);
#endif
        }

#if defined(CONFIG_X86_64)