[qemu.git] / hw / i386 / multiboot.c

/*
 * QEMU PC System Emulator
 *
 * Copyright (c) 2003-2004 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qemu/option.h"
#include "cpu.h"
#include "hw/nvram/fw_cfg.h"
#include "multiboot.h"
#include "hw/loader.h"
#include "elf.h"
#include "sysemu/sysemu.h"
#include "qemu/error-report.h"

/* Show multiboot debug output */
//#define DEBUG_MULTIBOOT

#ifdef DEBUG_MULTIBOOT
#define mb_debug(a...) error_report(a)
#else
#define mb_debug(a...)
#endif

#define MULTIBOOT_STRUCT_ADDR 0x9000

#if MULTIBOOT_STRUCT_ADDR > 0xf0000
#error multiboot struct needs to fit in 16 bit real mode
#endif

enum {
    /* Multiboot info */
    MBI_FLAGS       = 0,
    MBI_MEM_LOWER   = 4,
    MBI_MEM_UPPER   = 8,
    MBI_BOOT_DEVICE = 12,
    MBI_CMDLINE     = 16,
    MBI_MODS_COUNT  = 20,
    MBI_MODS_ADDR   = 24,
    MBI_MMAP_ADDR   = 48,
    MBI_BOOTLOADER  = 64,

    MBI_SIZE        = 88,

    /* Multiboot modules */
    MB_MOD_START    = 0,
    MB_MOD_END      = 4,
    MB_MOD_CMDLINE  = 8,

    MB_MOD_SIZE     = 16,

    /* Region offsets */
    ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
    ADDR_MBI      = ADDR_E820_MAP + 0x500,

    /* Multiboot flags */
    MULTIBOOT_FLAGS_MEMORY      = 1 << 0,
    MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
    MULTIBOOT_FLAGS_CMDLINE     = 1 << 2,
    MULTIBOOT_FLAGS_MODULES     = 1 << 3,
    MULTIBOOT_FLAGS_MMAP        = 1 << 6,
    MULTIBOOT_FLAGS_BOOTLOADER  = 1 << 9,
};

typedef struct {
    /* buffer holding kernel, cmdlines and mb_infos */
    void *mb_buf;
    /* address in target */
    hwaddr mb_buf_phys;
    /* size of mb_buf in bytes */
    unsigned mb_buf_size;
    /* offset of mb-info's in bytes */
    hwaddr offset_mbinfo;
    /* offset in buffer for cmdlines in bytes */
    hwaddr offset_cmdlines;
    /* offset in buffer for bootloader name in bytes */
    hwaddr offset_bootloader;
    /* offset of modules in bytes */
    hwaddr offset_mods;
    /* available slots for mb modules infos */
    int mb_mods_avail;
    /* currently used slots of mb modules */
    int mb_mods_count;
} MultibootState;

const char *bootloader_name = "qemu";

static uint32_t mb_add_cmdline(MultibootState *s, const char *cmdline)
{
    hwaddr p = s->offset_cmdlines;
    char *b = (char *)s->mb_buf + p;

    memcpy(b, cmdline, strlen(cmdline) + 1);
    s->offset_cmdlines += strlen(b) + 1;
    return s->mb_buf_phys + p;
}

static uint32_t mb_add_bootloader(MultibootState *s, const char *bootloader)
{
    hwaddr p = s->offset_bootloader;
    char *b = (char *)s->mb_buf + p;

    memcpy(b, bootloader, strlen(bootloader) + 1);
    s->offset_bootloader += strlen(b) + 1;
    return s->mb_buf_phys + p;
}

static void mb_add_mod(MultibootState *s,
                       hwaddr start, hwaddr end,
                       hwaddr cmdline_phys)
{
    char *p;
    assert(s->mb_mods_count < s->mb_mods_avail);

    p = (char *)s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE * s->mb_mods_count;

    stl_p(p + MB_MOD_START,   start);
    stl_p(p + MB_MOD_END,     end);
    stl_p(p + MB_MOD_CMDLINE, cmdline_phys);

    mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx,
             s->mb_mods_count, start, end);

    s->mb_mods_count++;
}

int load_multiboot(FWCfgState *fw_cfg,
                   FILE *f,
                   const char *kernel_filename,
                   const char *initrd_filename,
                   const char *kernel_cmdline,
                   int kernel_file_size,
                   uint8_t *header)
{
    int i, is_multiboot = 0;
    uint32_t flags = 0;
    uint32_t mh_entry_addr;
    uint32_t mh_load_addr;
    uint32_t mb_kernel_size;
    MultibootState mbs;
    uint8_t bootinfo[MBI_SIZE];
    uint8_t *mb_bootinfo_data;
    uint32_t cmdline_len;
    GList *mods = NULL;

    /* Ok, let's see if it is a multiboot image.
       The header is 12x32bit long, so the latest entry may be 8192 - 48. */
    for (i = 0; i < (8192 - 48); i += 4) {
        if (ldl_p(header+i) == 0x1BADB002) {
            uint32_t checksum = ldl_p(header+i+8);
            flags = ldl_p(header+i+4);
            checksum += flags;
            checksum += (uint32_t)0x1BADB002;
            if (!checksum) {
                is_multiboot = 1;
                break;
            }
        }
    }

    if (!is_multiboot)
        return 0; /* no multiboot */

    mb_debug("I believe we found a multiboot image!");
    memset(bootinfo, 0, sizeof(bootinfo));
    memset(&mbs, 0, sizeof(mbs));

    if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
        error_report("multiboot knows VBE. we don't");
    }
    if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
        uint64_t elf_entry;
        uint64_t elf_low, elf_high;
        int kernel_size;
        fclose(f);

        if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
            error_report("Cannot load x86-64 image, give a 32bit one.");
            exit(1);
        }

        kernel_size = load_elf(kernel_filename, NULL, NULL, NULL, &elf_entry,
                               &elf_low, &elf_high, 0, I386_ELF_MACHINE,
                               0, 0);
        if (kernel_size < 0) {
            error_report("Error while loading elf kernel");
            exit(1);
        }
        mh_load_addr = elf_low;
        mb_kernel_size = elf_high - elf_low;
        mh_entry_addr = elf_entry;

        mbs.mb_buf = g_malloc(mb_kernel_size);
        if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
            error_report("Error while fetching elf kernel from rom");
            exit(1);
        }

        mb_debug("loading multiboot-elf kernel "
                 "(%#x bytes) with entry %#zx",
                 mb_kernel_size, (size_t)mh_entry_addr);
    } else {
        /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
        uint32_t mh_header_addr = ldl_p(header+i+12);
        uint32_t mh_load_end_addr = ldl_p(header+i+20);
        uint32_t mh_bss_end_addr = ldl_p(header+i+24);

        mh_load_addr = ldl_p(header+i+16);
        if (mh_header_addr < mh_load_addr) {
            error_report("invalid load_addr address");
            exit(1);
        }
        if (mh_header_addr - mh_load_addr > i) {
            error_report("invalid header_addr address");
            exit(1);
        }

        uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
        uint32_t mb_load_size = 0;
        mh_entry_addr = ldl_p(header+i+28);

        if (mh_load_end_addr) {
            if (mh_load_end_addr < mh_load_addr) {
                error_report("invalid load_end_addr address");
                exit(1);
            }
            mb_load_size = mh_load_end_addr - mh_load_addr;
        } else {
            if (kernel_file_size < mb_kernel_text_offset) {
                error_report("invalid kernel_file_size");
                exit(1);
            }
            mb_load_size = kernel_file_size - mb_kernel_text_offset;
        }
        if (mb_load_size > UINT32_MAX - mh_load_addr) {
            error_report("kernel does not fit in address space");
            exit(1);
        }
        if (mh_bss_end_addr) {
            if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
                error_report("invalid bss_end_addr address");
                exit(1);
            }
            mb_kernel_size = mh_bss_end_addr - mh_load_addr;
        } else {
            mb_kernel_size = mb_load_size;
        }

        mb_debug("multiboot: header_addr = %#x", mh_header_addr);
        mb_debug("multiboot: load_addr = %#x", mh_load_addr);
        mb_debug("multiboot: load_end_addr = %#x", mh_load_end_addr);
        mb_debug("multiboot: bss_end_addr = %#x", mh_bss_end_addr);
        mb_debug("loading multiboot kernel (%#x bytes) at %#x",
                 mb_load_size, mh_load_addr);

        mbs.mb_buf = g_malloc(mb_kernel_size);
        fseek(f, mb_kernel_text_offset, SEEK_SET);
        if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
            error_report("fread() failed");
            exit(1);
        }
        memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
        fclose(f);
    }

    mbs.mb_buf_phys = mh_load_addr;

    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
    mbs.offset_mbinfo = mbs.mb_buf_size;

    /* Calculate space for cmdlines, bootloader name, and mb_mods */
    cmdline_len = strlen(kernel_filename) + 1;
    cmdline_len += strlen(kernel_cmdline) + 1;
    if (initrd_filename) {
        const char *r = initrd_filename;
        cmdline_len += strlen(initrd_filename) + 1;
        while (*r) {
            char *value;
            r = get_opt_value(r, &value);
            mbs.mb_mods_avail++;
            mods = g_list_append(mods, value);
            if (*r) {
                r++;
            }
        }
    }

    mbs.mb_buf_size += cmdline_len;
    mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
    mbs.mb_buf_size += strlen(bootloader_name) + 1;

    mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);

    /* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
    mbs.mb_buf            = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
    mbs.offset_cmdlines   = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
    mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;

    if (mods) {
        GList *tmpl = mods;
        mbs.offset_mods = mbs.mb_buf_size;

        while (tmpl) {
            char *next_space;
            int mb_mod_length;
            uint32_t offs = mbs.mb_buf_size;
            char *one_file = tmpl->data;

            /* if a space comes after the module filename, treat everything
               after that as parameters */
            hwaddr c = mb_add_cmdline(&mbs, one_file);
            next_space = strchr(one_file, ' ');
            if (next_space) {
                *next_space = '\0';
            }
            mb_debug("multiboot loading module: %s", one_file);
            mb_mod_length = get_image_size(one_file);
            if (mb_mod_length < 0) {
                error_report("Failed to open file '%s'", one_file);
                exit(1);
            }

            mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
            mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);

            if (load_image_size(one_file, (unsigned char *)mbs.mb_buf + offs,
                                mbs.mb_buf_size - offs) < 0) {
                error_report("Error loading file '%s'", one_file);
                exit(1);
            }
            mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
                       mbs.mb_buf_phys + offs + mb_mod_length, c);

            mb_debug("mod_start: %p\nmod_end:   %p\n  cmdline: "TARGET_FMT_plx,
                     (char *)mbs.mb_buf + offs,
                     (char *)mbs.mb_buf + offs + mb_mod_length, c);
            g_free(one_file);
            tmpl = tmpl->next;
        }
        g_list_free(mods);
    }

    /* Commandline support */
    char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
    snprintf(kcmdline, sizeof(kcmdline), "%s %s",
             kernel_filename, kernel_cmdline);
    stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));

    stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));

    stl_p(bootinfo + MBI_MODS_ADDR,  mbs.mb_buf_phys + mbs.offset_mbinfo);
    stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */

    /* the kernel is where we want it to be now */
    stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
                                | MULTIBOOT_FLAGS_BOOT_DEVICE
                                | MULTIBOOT_FLAGS_CMDLINE
                                | MULTIBOOT_FLAGS_MODULES
                                | MULTIBOOT_FLAGS_MMAP
                                | MULTIBOOT_FLAGS_BOOTLOADER);
    stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
    stl_p(bootinfo + MBI_MMAP_ADDR,   ADDR_E820_MAP);

    mb_debug("multiboot: entry_addr = %#x", mh_entry_addr);
    mb_debug("           mb_buf_phys   = "TARGET_FMT_plx, mbs.mb_buf_phys);
    mb_debug("           mod_start     = "TARGET_FMT_plx,
             mbs.mb_buf_phys + mbs.offset_mods);
    mb_debug("           mb_mods_count = %d", mbs.mb_mods_count);

    /* save bootinfo off the stack */
    mb_bootinfo_data = g_memdup(bootinfo, sizeof(bootinfo));

    /* Pass variables to option rom */
    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
    fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
                     mbs.mb_buf, mbs.mb_buf_size);

    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
    fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
    fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
                     sizeof(bootinfo));

    option_rom[nb_option_roms].name = "multiboot.bin";
    option_rom[nb_option_roms].bootindex = 0;
    nb_option_roms++;

    return 1; /* yes, we are multiboot */
}
Commit	Line	Data
52001445 AL	1	/*
	2	* QEMU PC System Emulator
	3	*
	4	* Copyright (c) 2003-2004 Fabrice Bellard
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
b6a0aa05	25	#include "qemu/osdep.h"
922a01a0	26	#include "qemu/option.h"
4771d756	27	#include "cpu.h"
0d09e41a	28	#include "hw/nvram/fw_cfg.h"
47b43a1f	29	#include "multiboot.h"
83c9f4ca	30	#include "hw/loader.h"
52001445	31	#include "elf.h"
9c17d615	32	#include "sysemu/sysemu.h"
4b9006a4	33	#include "qemu/error-report.h"
52001445 AL	34
	35	/* Show multiboot debug output */
	36	//#define DEBUG_MULTIBOOT
	37
	38	#ifdef DEBUG_MULTIBOOT
4b9006a4	39	#define mb_debug(a...) error_report(a)
52001445 AL	40	#else
	41	#define mb_debug(a...)
	42	#endif
	43
	44	#define MULTIBOOT_STRUCT_ADDR 0x9000
	45
	46	#if MULTIBOOT_STRUCT_ADDR > 0xf0000
	47	#error multiboot struct needs to fit in 16 bit real mode
	48	#endif
	49
	50	enum {
	51	/* Multiboot info */
	52	MBI_FLAGS = 0,
	53	MBI_MEM_LOWER = 4,
	54	MBI_MEM_UPPER = 8,
	55	MBI_BOOT_DEVICE = 12,
	56	MBI_CMDLINE = 16,
	57	MBI_MODS_COUNT = 20,
	58	MBI_MODS_ADDR = 24,
	59	MBI_MMAP_ADDR = 48,
5eba5a66	60	MBI_BOOTLOADER = 64,
52001445 AL	61
	62	MBI_SIZE = 88,
	63
	64	/* Multiboot modules */
	65	MB_MOD_START = 0,
	66	MB_MOD_END = 4,
	67	MB_MOD_CMDLINE = 8,
	68
	69	MB_MOD_SIZE = 16,
	70
	71	/* Region offsets */
	72	ADDR_E820_MAP = MULTIBOOT_STRUCT_ADDR + 0,
	73	ADDR_MBI = ADDR_E820_MAP + 0x500,
	74
	75	/* Multiboot flags */
	76	MULTIBOOT_FLAGS_MEMORY = 1 << 0,
	77	MULTIBOOT_FLAGS_BOOT_DEVICE = 1 << 1,
	78	MULTIBOOT_FLAGS_CMDLINE = 1 << 2,
	79	MULTIBOOT_FLAGS_MODULES = 1 << 3,
	80	MULTIBOOT_FLAGS_MMAP = 1 << 6,
5eba5a66	81	MULTIBOOT_FLAGS_BOOTLOADER = 1 << 9,
52001445 AL	82	};
	83
	84	typedef struct {
	85	/* buffer holding kernel, cmdlines and mb_infos */
	86	void *mb_buf;
	87	/* address in target */
a8170e5e	88	hwaddr mb_buf_phys;
52001445 AL	89	/* size of mb_buf in bytes */
	90	unsigned mb_buf_size;
	91	/* offset of mb-info's in bytes */
a8170e5e	92	hwaddr offset_mbinfo;
52001445	93	/* offset in buffer for cmdlines in bytes */
a8170e5e	94	hwaddr offset_cmdlines;
5eba5a66 DD	95	/* offset in buffer for bootloader name in bytes */
5eba5a66 DD	96	hwaddr offset_bootloader;
52001445	97	/* offset of modules in bytes */
a8170e5e	98	hwaddr offset_mods;
52001445 AL	99	/* available slots for mb modules infos */
	100	int mb_mods_avail;
	101	/* currently used slots of mb modules */
	102	int mb_mods_count;
	103	} MultibootState;
	104
5eba5a66 DD	105	const char *bootloader_name = "qemu";
5eba5a66 DD	106
52001445 AL	107	static uint32_t mb_add_cmdline(MultibootState s, const char cmdline)
52001445 AL	108	{
a8170e5e	109	hwaddr p = s->offset_cmdlines;
49e40b66	110	char b = (char )s->mb_buf + p;
52001445	111
96a3d392	112	memcpy(b, cmdline, strlen(cmdline) + 1);
49e40b66	113	s->offset_cmdlines += strlen(b) + 1;
52001445 AL	114	return s->mb_buf_phys + p;
	115	}
	116
5eba5a66 DD	117	static uint32_t mb_add_bootloader(MultibootState s, const char bootloader)
	118	{
	119	hwaddr p = s->offset_bootloader;
	120	char b = (char )s->mb_buf + p;
	121
	122	memcpy(b, bootloader, strlen(bootloader) + 1);
	123	s->offset_bootloader += strlen(b) + 1;
	124	return s->mb_buf_phys + p;
	125	}
	126
52001445	127	static void mb_add_mod(MultibootState *s,
a8170e5e AK	128	hwaddr start, hwaddr end,
a8170e5e AK	129	hwaddr cmdline_phys)
52001445 AL	130	{
	131	char *p;
	132	assert(s->mb_mods_count < s->mb_mods_avail);
	133
	134	p = (char )s->mb_buf + s->offset_mbinfo + MB_MOD_SIZE s->mb_mods_count;
	135
	136	stl_p(p + MB_MOD_START, start);
	137	stl_p(p + MB_MOD_END, end);
	138	stl_p(p + MB_MOD_CMDLINE, cmdline_phys);
	139
4b9006a4	140	mb_debug("mod%02d: "TARGET_FMT_plx" - "TARGET_FMT_plx,
bd418d90	141	s->mb_mods_count, start, end);
52001445 AL	142
	143	s->mb_mods_count++;
	144	}
	145
a88b362c	146	int load_multiboot(FWCfgState *fw_cfg,
52001445 AL	147	FILE *f,
	148	const char *kernel_filename,
	149	const char *initrd_filename,
	150	const char *kernel_cmdline,
	151	int kernel_file_size,
	152	uint8_t *header)
	153	{
	154	int i, is_multiboot = 0;
	155	uint32_t flags = 0;
	156	uint32_t mh_entry_addr;
	157	uint32_t mh_load_addr;
	158	uint32_t mb_kernel_size;
	159	MultibootState mbs;
	160	uint8_t bootinfo[MBI_SIZE];
	161	uint8_t *mb_bootinfo_data;
b4168498	162	uint32_t cmdline_len;
f8da93a0	163	GList *mods = NULL;
52001445 AL	164
	165	/* Ok, let's see if it is a multiboot image.
	166	The header is 12x32bit long, so the latest entry may be 8192 - 48. */
	167	for (i = 0; i < (8192 - 48); i += 4) {
	168	if (ldl_p(header+i) == 0x1BADB002) {
	169	uint32_t checksum = ldl_p(header+i+8);
	170	flags = ldl_p(header+i+4);
	171	checksum += flags;
	172	checksum += (uint32_t)0x1BADB002;
	173	if (!checksum) {
	174	is_multiboot = 1;
	175	break;
	176	}
	177	}
	178	}
	179
	180	if (!is_multiboot)
	181	return 0; /* no multiboot */
	182
371b74e2	183	mb_debug("I believe we found a multiboot image!");
52001445 AL	184	memset(bootinfo, 0, sizeof(bootinfo));
	185	memset(&mbs, 0, sizeof(mbs));
	186
	187	if (flags & 0x00000004) { /* MULTIBOOT_HEADER_HAS_VBE */
371b74e2	188	error_report("multiboot knows VBE. we don't");
52001445 AL	189	}
	190	if (!(flags & 0x00010000)) { /* MULTIBOOT_HEADER_HAS_ADDR */
	191	uint64_t elf_entry;
	192	uint64_t elf_low, elf_high;
	193	int kernel_size;
	194	fclose(f);
96968466 AL	195
96968466 AL	196	if (((struct elf64_hdr*)header)->e_machine == EM_X86_64) {
4b9006a4	197	error_report("Cannot load x86-64 image, give a 32bit one.");
96968466 AL	198	exit(1);
	199	}
	200
4366e1db	201	kernel_size = load_elf(kernel_filename, NULL, NULL, NULL, &elf_entry,
7ef295ea PC	202	&elf_low, &elf_high, 0, I386_ELF_MACHINE,
7ef295ea PC	203	0, 0);
52001445	204	if (kernel_size < 0) {
4b9006a4	205	error_report("Error while loading elf kernel");
52001445 AL	206	exit(1);
	207	}
	208	mh_load_addr = elf_low;
	209	mb_kernel_size = elf_high - elf_low;
	210	mh_entry_addr = elf_entry;
	211
7267c094	212	mbs.mb_buf = g_malloc(mb_kernel_size);
52001445	213	if (rom_copy(mbs.mb_buf, mh_load_addr, mb_kernel_size) != mb_kernel_size) {
4b9006a4	214	error_report("Error while fetching elf kernel from rom");
52001445 AL	215	exit(1);
	216	}
	217
371b74e2	218	mb_debug("loading multiboot-elf kernel "
4b9006a4 JS	219	"(%#x bytes) with entry %#zx",
4b9006a4 JS	220	mb_kernel_size, (size_t)mh_entry_addr);
52001445 AL	221	} else {
	222	/* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_ADDR. */
	223	uint32_t mh_header_addr = ldl_p(header+i+12);
6b8273a1 GW	224	uint32_t mh_load_end_addr = ldl_p(header+i+20);
6b8273a1 GW	225	uint32_t mh_bss_end_addr = ldl_p(header+i+24);
ed4f86e8	226
52001445	227	mh_load_addr = ldl_p(header+i+16);
ed4f86e8	228	if (mh_header_addr < mh_load_addr) {
4b9006a4	229	error_report("invalid load_addr address");
ed4f86e8 PP	230	exit(1);
ed4f86e8 PP	231	}
dbf2dce7 KW	232	if (mh_header_addr - mh_load_addr > i) {
	233	error_report("invalid header_addr address");
	234	exit(1);
	235	}
ed4f86e8	236
52001445	237	uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr);
9c3a596a	238	uint32_t mb_load_size = 0;
52001445	239	mh_entry_addr = ldl_p(header+i+28);
9c3a596a SM	240
9c3a596a SM	241	if (mh_load_end_addr) {
ed4f86e8	242	if (mh_load_end_addr < mh_load_addr) {
4b9006a4	243	error_report("invalid load_end_addr address");
ed4f86e8 PP	244	exit(1);
ed4f86e8 PP	245	}
9c3a596a SM	246	mb_load_size = mh_load_end_addr - mh_load_addr;
9c3a596a SM	247	} else {
ed4f86e8	248	if (kernel_file_size < mb_kernel_text_offset) {
4b9006a4	249	error_report("invalid kernel_file_size");
ed4f86e8 PP	250	exit(1);
ed4f86e8 PP	251	}
2a8fcd11 JS	252	mb_load_size = kernel_file_size - mb_kernel_text_offset;
2a8fcd11 JS	253	}
b17a9054 KW	254	if (mb_load_size > UINT32_MAX - mh_load_addr) {
	255	error_report("kernel does not fit in address space");
	256	exit(1);
	257	}
2a8fcd11 JS	258	if (mh_bss_end_addr) {
2a8fcd11 JS	259	if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) {
4b9006a4	260	error_report("invalid bss_end_addr address");
2a8fcd11 JS	261	exit(1);
	262	}
	263	mb_kernel_size = mh_bss_end_addr - mh_load_addr;
	264	} else {
	265	mb_kernel_size = mb_load_size;
9c3a596a	266	}
52001445	267
4b9006a4 JS	268	mb_debug("multiboot: header_addr = %#x", mh_header_addr);
	269	mb_debug("multiboot: load_addr = %#x", mh_load_addr);
	270	mb_debug("multiboot: load_end_addr = %#x", mh_load_end_addr);
	271	mb_debug("multiboot: bss_end_addr = %#x", mh_bss_end_addr);
371b74e2	272	mb_debug("loading multiboot kernel (%#x bytes) at %#x",
6b8273a1	273	mb_load_size, mh_load_addr);
52001445	274
7267c094	275	mbs.mb_buf = g_malloc(mb_kernel_size);
52001445	276	fseek(f, mb_kernel_text_offset, SEEK_SET);
6b8273a1	277	if (fread(mbs.mb_buf, 1, mb_load_size, f) != mb_load_size) {
4b9006a4	278	error_report("fread() failed");
52001445 AL	279	exit(1);
52001445 AL	280	}
6b8273a1	281	memset(mbs.mb_buf + mb_load_size, 0, mb_kernel_size - mb_load_size);
52001445 AL	282	fclose(f);
	283	}
	284
	285	mbs.mb_buf_phys = mh_load_addr;
	286
	287	mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_kernel_size);
	288	mbs.offset_mbinfo = mbs.mb_buf_size;
	289
5eba5a66	290	/* Calculate space for cmdlines, bootloader name, and mb_mods */
b4168498 KW	291	cmdline_len = strlen(kernel_filename) + 1;
b4168498 KW	292	cmdline_len += strlen(kernel_cmdline) + 1;
52001445	293	if (initrd_filename) {
f8da93a0	294	const char *r = initrd_filename;
6e3ad3f0	295	cmdline_len += strlen(initrd_filename) + 1;
f8da93a0 DB	296	while (*r) {
	297	char *value;
	298	r = get_opt_value(r, &value);
950c4e6c	299	mbs.mb_mods_avail++;
f8da93a0 DB	300	mods = g_list_append(mods, value);
	301	if (*r) {
	302	r++;
950c4e6c	303	}
52001445	304	}
52001445 AL	305	}
52001445 AL	306
b4168498 KW	307	mbs.mb_buf_size += cmdline_len;
	308	mbs.mb_buf_size += MB_MOD_SIZE * mbs.mb_mods_avail;
	309	mbs.mb_buf_size += strlen(bootloader_name) + 1;
	310
52001445 AL	311	mbs.mb_buf_size = TARGET_PAGE_ALIGN(mbs.mb_buf_size);
52001445 AL	312
5eba5a66 DD	313	/* enlarge mb_buf to hold cmdlines, bootloader, mb-info structs */
	314	mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
	315	mbs.offset_cmdlines = mbs.offset_mbinfo + mbs.mb_mods_avail * MB_MOD_SIZE;
b4168498	316	mbs.offset_bootloader = mbs.offset_cmdlines + cmdline_len;
52001445	317
f8da93a0 DB	318	if (mods) {
f8da93a0 DB	319	GList *tmpl = mods;
52001445 AL	320	mbs.offset_mods = mbs.mb_buf_size;
52001445 AL	321
f8da93a0	322	while (tmpl) {
52001445	323	char *next_space;
37a05af0	324	int mb_mod_length;
52001445	325	uint32_t offs = mbs.mb_buf_size;
f8da93a0	326	char *one_file = tmpl->data;
52001445	327
52001445 AL	328	/* if a space comes after the module filename, treat everything
52001445 AL	329	after that as parameters */
950c4e6c DB	330	hwaddr c = mb_add_cmdline(&mbs, one_file);
	331	next_space = strchr(one_file, ' ');
	332	if (next_space) {
52001445	333	*next_space = '\0';
950c4e6c DB	334	}
	335	mb_debug("multiboot loading module: %s", one_file);
	336	mb_mod_length = get_image_size(one_file);
52001445	337	if (mb_mod_length < 0) {
950c4e6c	338	error_report("Failed to open file '%s'", one_file);
52001445 AL	339	exit(1);
	340	}
	341
	342	mbs.mb_buf_size = TARGET_PAGE_ALIGN(mb_mod_length + mbs.mb_buf_size);
7267c094	343	mbs.mb_buf = g_realloc(mbs.mb_buf, mbs.mb_buf_size);
52001445	344
5250b09e PM	345	if (load_image_size(one_file, (unsigned char *)mbs.mb_buf + offs,
	346	mbs.mb_buf_size - offs) < 0) {
	347	error_report("Error loading file '%s'", one_file);
	348	exit(1);
	349	}
52001445 AL	350	mb_add_mod(&mbs, mbs.mb_buf_phys + offs,
	351	mbs.mb_buf_phys + offs + mb_mod_length, c);
	352
4b9006a4	353	mb_debug("mod_start: %p\nmod_end: %p\n cmdline: "TARGET_FMT_plx,
52001445 AL	354	(char *)mbs.mb_buf + offs,
52001445 AL	355	(char *)mbs.mb_buf + offs + mb_mod_length, c);
950c4e6c	356	g_free(one_file);
f8da93a0 DB	357	tmpl = tmpl->next;
	358	}
	359	g_list_free(mods);
52001445 AL	360	}
	361
	362	/* Commandline support */
	363	char kcmdline[strlen(kernel_filename) + strlen(kernel_cmdline) + 2];
	364	snprintf(kcmdline, sizeof(kcmdline), "%s %s",
	365	kernel_filename, kernel_cmdline);
	366	stl_p(bootinfo + MBI_CMDLINE, mb_add_cmdline(&mbs, kcmdline));
	367
5eba5a66 DD	368	stl_p(bootinfo + MBI_BOOTLOADER, mb_add_bootloader(&mbs, bootloader_name));
5eba5a66 DD	369
52001445 AL	370	stl_p(bootinfo + MBI_MODS_ADDR, mbs.mb_buf_phys + mbs.offset_mbinfo);
	371	stl_p(bootinfo + MBI_MODS_COUNT, mbs.mb_mods_count); /* mods_count */
	372
	373	/* the kernel is where we want it to be now */
	374	stl_p(bootinfo + MBI_FLAGS, MULTIBOOT_FLAGS_MEMORY
	375	\| MULTIBOOT_FLAGS_BOOT_DEVICE
	376	\| MULTIBOOT_FLAGS_CMDLINE
	377	\| MULTIBOOT_FLAGS_MODULES
5eba5a66 DD	378	\| MULTIBOOT_FLAGS_MMAP
5eba5a66 DD	379	\| MULTIBOOT_FLAGS_BOOTLOADER);
c83066d4	380	stl_p(bootinfo + MBI_BOOT_DEVICE, 0x8000ffff); /* XXX: use the -boot switch? */
52001445 AL	381	stl_p(bootinfo + MBI_MMAP_ADDR, ADDR_E820_MAP);
52001445 AL	382
4b9006a4 JS	383	mb_debug("multiboot: entry_addr = %#x", mh_entry_addr);
	384	mb_debug(" mb_buf_phys = "TARGET_FMT_plx, mbs.mb_buf_phys);
	385	mb_debug(" mod_start = "TARGET_FMT_plx,
	386	mbs.mb_buf_phys + mbs.offset_mods);
	387	mb_debug(" mb_mods_count = %d", mbs.mb_mods_count);
52001445 AL	388
52001445 AL	389	/* save bootinfo off the stack */
ad2c1993	390	mb_bootinfo_data = g_memdup(bootinfo, sizeof(bootinfo));
52001445 AL	391
	392	/* Pass variables to option rom */
	393	fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ENTRY, mh_entry_addr);
	394	fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, mh_load_addr);
	395	fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, mbs.mb_buf_size);
	396	fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA,
	397	mbs.mb_buf, mbs.mb_buf_size);
	398
	399	fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, ADDR_MBI);
	400	fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, sizeof(bootinfo));
	401	fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, mb_bootinfo_data,
	402	sizeof(bootinfo));
	403
2e55e842 GN	404	option_rom[nb_option_roms].name = "multiboot.bin";
2e55e842 GN	405	option_rom[nb_option_roms].bootindex = 0;
52001445 AL	406	nb_option_roms++;
	407
	408	return 1; /* yes, we are multiboot */
	409	}