#ifndef MULTIBOOT_H
#define MULTIBOOT_H

#include "hos_types.h"

#ifdef __cplusplus
extern "C" {
#endif

/* The magic number for the Multiboot header. */
#define MB_HEADER_MAGIC             0x1BADB002
#define MB_HEADER_FLAGS             0x00000003

#define MB_HEADER_ALIGN_MODULES     (1 << 0)
#define MB_HEADER_MEM_INFO          (1 << 1)
#define MB_HEADER_VIDEO_INFO        (1 << 2)
#define MB_HEADER_KLUDGE_OFFSETS    (1 << 16)

/* The magic number passed by a Multiboot-compliant boot loader. */
#define MB_BOOTLOADER_MAGIC         0x2BADB002

#define MB_BOOTLOADER_MEM_INFO      (1 << 0)
#define MB_BOOTLOADER_BOOT_DEVICE   (1 << 1)
#define MB_BOOTLOADER_COMMAND_LINE  (1 << 2)
#define MB_BOOTLOADER_MODS          (1 << 3)
#define MB_BOOTLOADER_AOUT          (1 << 4)
#define MB_BOOTLOADER_ELF           (1 << 5)
#define MB_BOOTLOADER_MMAP          (1 << 6)
#define MB_BOOTLOADER_DRIVES        (1 << 7)
#define MB_BOOTLOADER_CONFIG        (1 << 8)
#define MB_BOOTLOADER_APM           (1 << 9)
#define MB_BOOTLOADER_GRAPHICS      (1 << 10)

#define MB_DRIVE_MODE_CHS           0
#define MB_DRIVE_MODE_LBA           1

#define MB_MMAP_TYPE_RAM            1

/* The Multiboot header. */
typedef struct
{
    u32_t   magic;
    u32_t   flags;
    u32_t   checksum;
    u32_t   header_addr;        // if flags[16]
    u32_t   load_addr;          // if flags[16]
    u32_t   load_end_addr;      // if flags[16]
    u32_t   bss_end_addr;       // if flags[16]
    u32_t   entry_addr;         // if flags[16]
    u32_t   mode_type;          // if flags[2]
    u32_t   width;              // if flags[2]
    u32_t   height;             // if flags[2]
    u32_t   depth;              // if flags[2]
} mb_header_t;

/* The symbol table for a.out. */
typedef struct
{
    u32_t   tabsize;
    u32_t   strsize;
    u32_t   addr;
    u32_t   reserved;
} mb_aout_symbol_table_t;

/* The section header table for ELF. */
typedef struct
{
    u32_t   num;
    u32_t   size;
    u32_t   addr;
    u32_t   shndx;
} mb_elf_section_header_table_t;

/* The Multiboot information. */
typedef struct
{
    u32_t   flags;
    u32_t   mem_lower;          // present if flags[0] is set
    u32_t   mem_upper;
    u32_t   boot_device;        // 1
    u32_t   cmdline;            // 2
    u32_t   mods_count;         // 3
    u32_t   mods_addr;          // 3
    union
    {
        mb_aout_symbol_table_t          aout_sym;   // 4
        mb_elf_section_header_table_t   elf_sec;    // 5
    };
    u32_t   mmap_length;        // 6
    u32_t   mmap_addr;          // 6
    u32_t   drives_length;      // 7
    u32_t   drives_addr;        // 7
    u32_t   config_table;       // 8
    u32_t   bootloader_name;    // 9
    u32_t   apm_table;          // 10

    u32_t   vbe_control_info;   // 11
    u32_t   vbe_mode_info;      // 11
    u16_t   vbe_mode;           // 11
    u16_t   vbe_interface_seg;  // 11
    u16_t   vbe_interface_off;  // 11
    u16_t   vbe_interface_len;  // 11
} mb_info_t;

/* The module structure. */
typedef struct
{
    u32_t   mod_start;
    u32_t   mod_end;
    u32_t   string;
    u32_t   reserved;
} mb_module_t;

/* The memory map. Be careful that the offset 0 is base_addr_low, not size. */
typedef struct
{
    u32_t   size;                 // offset -4
    u64_t   base;                 // offset 0
    u64_t   length;
    u32_t   type;
} mb_mmap_t;

/* The drive structure */
typedef struct
{
    u32_t   size;
    u8_t    drive_number;
    u8_t    drive_mode;
    u8_t    drive_cylinders;
    u8_t    drive_heads;
    u8_t    drive_sectors;
    u16_t   drive_ports[1];
} mb_drive_t;

/* APM table structure */
typedef struct
{
    u16_t   version;
    u16_t   cseg;
    u32_t   offset;
    u16_t   cseg_16;
    u16_t   dseg;
    u16_t   flags;
    u16_t   cseg_len;
    u16_t   cseg_16_len;
    u16_t   dseg_len;
} mb_apm_t;

#ifdef __cplusplus
}
#endif

#endif