source: bootcd/isolinux/syslinux-6.03/com32/mboot/mb_info.h

/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 2000  Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *  The structure type "mod_list" is used by the "multiboot_info" structure.
 */

#ifndef MBOOT_MB_INFO_H
#define MBOOT_MB_INFO_H

#include <inttypes.h>

struct mod_list {
    /* the memory used goes from bytes 'mod_start' to 'mod_end-1' inclusive */
    uint32_t mod_start;
    uint32_t mod_end;

    /* Module command line */
    uint32_t cmdline;

    /* padding to take it to 16 bytes (must be zero) */
    uint32_t pad;
};

/*
 *  INT-15, AX=E820 style "AddressRangeDescriptor"
 *  ...with a "size" parameter on the front which is the structure size - 4,
 *  pointing to the next one, up until the full buffer length of the memory
 *  map has been reached.
 */

struct AddrRangeDesc {
    uint32_t size;
    uint64_t BaseAddr;
    uint64_t Length;
    uint32_t Type;
    /* unspecified optional padding... */
} __attribute__ ((packed));

/* usable memory "Type", all others are reserved.  */
#define MB_ARD_MEMORY           1

/* Drive Info structure.  */
struct drive_info {
    /* The size of this structure.  */
    uint32_t size;

    /* The BIOS drive number.  */
    uint8_t drive_number;

    /* The access mode (see below).  */
    uint8_t drive_mode;

    /* The BIOS geometry.  */
    uint16_t drive_cylinders;
    uint8_t drive_heads;
    uint8_t drive_sectors;

    /* The array of I/O ports used for the drive.  */
    uint16_t drive_ports[0];
};

/* Drive Mode.  */
#define MB_DI_CHS_MODE          0
#define MB_DI_LBA_MODE          1

/* APM BIOS info.  */
struct apm_info {
    uint16_t version;
    uint16_t cseg;
    uint32_t offset;
    uint16_t cseg_16;
    uint16_t dseg_16;
    uint16_t cseg_len;
    uint16_t cseg_16_len;
    uint16_t dseg_16_len;
};

/*
 *  MultiBoot Info description
 *
 *  This is the struct passed to the boot image.  This is done by placing
 *  its address in the EAX register.
 */

struct multiboot_info {
    /* MultiBoot info version number */
    uint32_t flags;

    /* Available memory from BIOS */
    uint32_t mem_lower;
    uint32_t mem_upper;

    /* "root" partition */
    uint32_t boot_device;

    /* Kernel command line */
    uint32_t cmdline;

    /* Boot-Module list */
    uint32_t mods_count;
    uint32_t mods_addr;

    union {
        struct {
            /* (a.out) Kernel symbol table info */
            uint32_t tabsize;
            uint32_t strsize;
            uint32_t addr;
            uint32_t pad;
        } a;
        struct {
            /* (ELF) Kernel section header table */
            uint32_t num;
            uint32_t size;
            uint32_t addr;
            uint32_t shndx;
        } e;
    } syms;

    /* Memory Mapping buffer */
    uint32_t mmap_length;
    uint32_t mmap_addr;

    /* Drive Info buffer */
    uint32_t drives_length;
    uint32_t drives_addr;

    /* ROM configuration table */
    uint32_t config_table;

    /* Boot Loader Name */
    uint32_t boot_loader_name;

    /* APM table */
    uint32_t apm_table;

    /* Video */
    uint32_t vbe_control_info;
    uint32_t vbe_mode_info;
    uint16_t vbe_mode;
    uint16_t vbe_interface_seg;
    uint16_t vbe_interface_off;
    uint16_t vbe_interface_len;
};

/*
 *  Flags to be set in the 'flags' parameter above
 */

/* is there basic lower/upper memory information? */
#define MB_INFO_MEMORY                  0x00000001
/* is there a boot device set? */
#define MB_INFO_BOOTDEV                 0x00000002
/* is the command-line defined? */
#define MB_INFO_CMDLINE                 0x00000004
/* are there modules to do something with? */
#define MB_INFO_MODS                    0x00000008

/* These next two are mutually exclusive */

/* is there a symbol table loaded? */
#define MB_INFO_AOUT_SYMS               0x00000010
/* is there an ELF section header table? */
#define MB_INFO_ELF_SHDR                0x00000020

/* is there a full memory map? */
#define MB_INFO_MEM_MAP                 0x00000040

/* Is there drive info?  */
#define MB_INFO_DRIVE_INFO              0x00000080

/* Is there a config table?  */
#define MB_INFO_CONFIG_TABLE            0x00000100

/* Is there a boot loader name?  */
#define MB_INFO_BOOT_LOADER_NAME        0x00000200

/* Is there a APM table?  */
#define MB_INFO_APM_TABLE               0x00000400

/* Is there video information?  */
#define MB_INFO_VIDEO_INFO              0x00000800

/*
 *  The following value must be present in the EAX register.
 */

#define MULTIBOOT_VALID                 0x2BADB002

#endif /* MBOOT_MB_INFO_H */