mbr.hpp

// More or less a copy of mbr.hpp in IncludeOS

#pragma once

#include <string>
#include <cstdint>

struct MBR {
  static constexpr int PARTITIONS {4};

  struct partition {
    uint8_t  flags;
    uint8_t  CHS_BEG[3];
    uint8_t  type;
    uint8_t  CHS_END[3];
    uint32_t lba_begin;
    uint32_t sectors;
  } __attribute__((packed));

  /** Legacy BIOS Parameter Block */
  struct BPB {
    uint16_t bytes_per_sector;
    uint8_t  sectors_per_cluster;
    uint16_t reserved_sectors;
    uint8_t  fa_tables;
    uint16_t root_entries;
    uint16_t small_sectors;
    uint8_t  media_type;       // 0xF8 == hard drive
    uint16_t sectors_per_fat;
    uint16_t sectors_per_track;
    uint16_t num_heads;
    uint32_t hidden_sectors;
    uint32_t large_sectors;    // Used if small_sectors == 0
    uint8_t  disk_number;      // Starts at 0x80
    uint8_t  current_head;
    uint8_t  signature;        // Must be 0x28 or 0x29
    uint32_t serial_number;    // Unique ID created by mkfs
    char     volume_label[11]; // Deprecated
    char     system_id[8];     // FAT12 or FAT16
  } __attribute__((packed));

  struct mbr {
    uint8_t   jump[3];
    char      oem_name[8];
    uint8_t   boot[435];       // Boot-code
    partition part[PARTITIONS];
    uint16_t  magic;           // 0xAA55

    inline BPB* bpb() noexcept
    { return reinterpret_cast<BPB*>(boot); }
  } __attribute__((packed));

  static std::string id_to_name(uint8_t);
}; //< struct MBR