#define PACKED __attribute__((packed))

#define TYPE_EMPTY  "00000000-0000-0000-0000-000000000000"
#define TYPE_SYSTEM "C12A7328-F81F-11D2-BA4B-00A0C93EC93B"

typedef PACKED struct
{
  uint8_t d[16];
} GUID;

#define GPT_ENTRY_FLAG_SYSTEM 1
typedef PACKED struct
{
  GUID type;
  GUID label;
  uint64_t start;
  uint64_t end;
  uint64_t flags;
  uint8_t name[72];
} GPT_entry;

#define GPT_HEADER_SIGNATURE "EFI PART"
#define GPT_HEADER_REVISION_EFI10 0x00010000

typedef PACKED struct
{
  uint8_t signature[8];
  uint32_t revision;
  uint32_t header_size;
  uint32_t header_crc;
  uint8_t reserved[20];
  uint64_t my_lba;
  uint64_t alternate_lba;
  uint64_t first_usable_lba;
  uint64_t last_usable_lba;
  GUID disk_guid;
  uint64_t partition_entry_lba;
  uint32_t n_partition_entries;
  uint32_t partition_entry_size;
  uint32_t partition_entry_crc;
} GPT_header;




#define MBR_PARTITION_TYPE_EFI 0xee
#define MBR_PARTITION_BOOTABLE 0x80

typedef PACKED struct
{
  uint8_t head;
  uint8_t sector;
  uint8_t track;
} CHS;

typedef PACKED struct
{
  uint8_t bootable;
  CHS chs_start;
  uint8_t system;
  CHS chs_end;
  uint32_t start;
  uint32_t size;
} MBR_entry;

typedef PACKED struct
{
  uint8_t boot_code[440];
  uint8_t uid[4];
  uint8_t reserved[2];
  MBR_entry entry[4];
  uint8_t signature[2];
} MBR;