// Taken from https://www.gnu.org/software/grub/manual/multiboot/multiboot.html#multiboot_002eh
/* multiboot.h - Multiboot header file. */
/* Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
 *
 *  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 ANY
 *  DEVELOPER OR DISTRIBUTOR 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.
 */

#ifndef MULTIBOOT_HEADER
#define MULTIBOOT_HEADER 1

/* How many bytes from the start of the file we search for the header. */
#define MULTIBOOT_SEARCH 8192
#define MULTIBOOT_HEADER_ALIGN 4

/* The magic field should contain this. */
#define MULTIBOOT_HEADER_MAGIC 0x1BADB002

/* This should be in %eax. */
#define MULTIBOOT_BOOTLOADER_MAGIC 0x2BADB002

/* Alignment of multiboot modules. */
#define MULTIBOOT_MOD_ALIGN 0x00001000

/* Alignment of the multiboot info structure. */
#define MULTIBOOT_INFO_ALIGN 0x00000004

/* Flags set in the 'flags' member of the multiboot header. */

/* Align all boot modules on i386 page (4KB) boundaries. */
#define MULTIBOOT_PAGE_ALIGN 0x00000001

/* Must pass memory information to OS. */
#define MULTIBOOT_MEMORY_INFO 0x00000002

/* Must pass video information to OS. */
#define MULTIBOOT_VIDEO_MODE 0x00000004

/* This flag indicates the use of the address fields in the header. */
#define MULTIBOOT_AOUT_KLUDGE 0x00010000

/* Flags to be set in the 'flags' member of the multiboot info structure. */

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

/* These next two are mutually exclusive */

/* is there a symbol table loaded? */
#define MULTIBOOT_INFO_AOUT_SYMS 0x00000010
/* is there an ELF section header table? */
#define MULTIBOOT_INFO_ELF_SHDR 0X00000020

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

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

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

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

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

/* Is there video information? */
#define MULTIBOOT_INFO_VBE_INFO 0x00000800
#define MULTIBOOT_INFO_FRAMEBUFFER_INFO 0x00001000

#ifndef ASM_FILE

typedef unsigned char multiboot_uint8_t;
typedef unsigned short multiboot_uint16_t;
typedef unsigned int multiboot_uint32_t;
typedef unsigned long long multiboot_uint64_t;

struct multiboot_header {
    /* Must be MULTIBOOT_MAGIC - see above. */
    multiboot_uint32_t magic;

    /* Feature flags. */
    multiboot_uint32_t flags;

    /* The above fields plus this one must equal 0 mod 2^32. */
    multiboot_uint32_t checksum;

    /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
    multiboot_uint32_t header_addr;
    multiboot_uint32_t load_addr;
    multiboot_uint32_t load_end_addr;
    multiboot_uint32_t bss_end_addr;
    multiboot_uint32_t entry_addr;

    /* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
    multiboot_uint32_t mode_type;
    multiboot_uint32_t width;
    multiboot_uint32_t height;
    multiboot_uint32_t depth;
};

/* The symbol table for a.out. */
struct multiboot_aout_symbol_table {
    multiboot_uint32_t tabsize;
    multiboot_uint32_t strsize;
    multiboot_uint32_t addr;
    multiboot_uint32_t reserved;
};
typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;

/* The section header table for ELF. */
struct multiboot_elf_section_header_table {
    multiboot_uint32_t num;
    multiboot_uint32_t size;
    multiboot_uint32_t addr;
    multiboot_uint32_t shndx;
};
typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;

struct multiboot_info {
    /* Multiboot info version number */
    multiboot_uint32_t flags;

    /* Available memory from BIOS */
    multiboot_uint32_t mem_lower;
    multiboot_uint32_t mem_upper;

    /* "root" partition */
    multiboot_uint32_t boot_device;

    /* Kernel command line */
    multiboot_uint32_t cmdline;

    /* Boot-Module list */
    multiboot_uint32_t mods_count;
    multiboot_uint32_t mods_addr;

    union {
        multiboot_aout_symbol_table_t aout_sym;
        multiboot_elf_section_header_table_t elf_sec;
    } u;

    /* Memory Mapping buffer */
    multiboot_uint32_t mmap_length;
    multiboot_uint32_t mmap_addr;

    /* Drive Info buffer */
    multiboot_uint32_t drives_length;
    multiboot_uint32_t drives_addr;

    /* ROM configuration table */
    multiboot_uint32_t config_table;

    /* Boot Loader Name */
    multiboot_uint32_t boot_loader_name;

    /* APM table */
    multiboot_uint32_t apm_table;

    /* Video */
    multiboot_uint32_t vbe_control_info;
    multiboot_uint32_t vbe_mode_info;
    multiboot_uint16_t vbe_mode;
    multiboot_uint16_t vbe_interface_seg;
    multiboot_uint16_t vbe_interface_off;
    multiboot_uint16_t vbe_interface_len;

    multiboot_uint64_t framebuffer_addr;
    multiboot_uint32_t framebuffer_pitch;
    multiboot_uint32_t framebuffer_width;
    multiboot_uint32_t framebuffer_height;
    multiboot_uint8_t framebuffer_bpp;
#define MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED 0
#define MULTIBOOT_FRAMEBUFFER_TYPE_RGB 1
#define MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT 2
    multiboot_uint8_t framebuffer_type;
    union {
        struct {
            multiboot_uint32_t framebuffer_palette_addr;
            multiboot_uint16_t framebuffer_palette_num_colors;
        };
        struct {
            multiboot_uint8_t framebuffer_red_field_position;
            multiboot_uint8_t framebuffer_red_mask_size;
            multiboot_uint8_t framebuffer_green_field_position;
            multiboot_uint8_t framebuffer_green_mask_size;
            multiboot_uint8_t framebuffer_blue_field_position;
            multiboot_uint8_t framebuffer_blue_mask_size;
        };
    };
};
typedef struct multiboot_info multiboot_info_t;

struct multiboot_color {
    multiboot_uint8_t red;
    multiboot_uint8_t green;
    multiboot_uint8_t blue;
};

struct multiboot_mmap_entry {
    multiboot_uint32_t size;
    multiboot_uint64_t addr;
    multiboot_uint64_t len;
#define MULTIBOOT_MEMORY_AVAILABLE 1
#define MULTIBOOT_MEMORY_RESERVED 2
#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE 3
#define MULTIBOOT_MEMORY_NVS 4
#define MULTIBOOT_MEMORY_BADRAM 5
    multiboot_uint32_t type;
} __attribute__((packed));
typedef struct multiboot_mmap_entry multiboot_memory_map_t;

struct multiboot_mod_list {
    /* the memory used goes from bytes 'mod_start' to 'mod_end-1' inclusive */
    multiboot_uint32_t mod_start;
    multiboot_uint32_t mod_end;

    /* Module command line */
    multiboot_uint32_t cmdline;

    /* padding to take it to 16 bytes (must be zero) */
    multiboot_uint32_t pad;
};
typedef struct multiboot_mod_list multiboot_module_t;

/* APM BIOS info. */
struct multiboot_apm_info {
    multiboot_uint16_t version;
    multiboot_uint16_t cseg;
    multiboot_uint32_t offset;
    multiboot_uint16_t cseg_16;
    multiboot_uint16_t dseg;
    multiboot_uint16_t flags;
    multiboot_uint16_t cseg_len;
    multiboot_uint16_t cseg_16_len;
    multiboot_uint16_t dseg_len;
};

#endif /* ! ASM_FILE */

#endif /* ! MULTIBOOT_HEADER */