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/* mbr.h -- MBR data structure definitions, types, and functions */
#include <stdint.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#ifndef __MBRSTRUCTS
#define __MBRSTRUCTS
#define MBR_SIGNATURE UINT16_C(0xAA55)
// Maximum number of logical partitions supported
#define NUM_LOGICALS 124
using namespace std;
/****************************************
* *
* MBRData class and related structures *
* *
****************************************/
// Data for a single MBR partition record
// Note that firstSector and lastSector are in CHS addressing, which
// splits the bits up in a weird way.
struct MBRRecord {
uint8_t status;
uint8_t firstSector[3];
uint8_t partitionType;
uint8_t lastSector[3];
uint32_t firstLBA;
uint32_t lengthLBA;
}; // struct MBRRecord
// Extended Boot Record (EBR) data, used to hold one logical partition's
// data within an extended partition. Includes pointer to next record for
// in-memory linked-list access. This is similar to MBRData, but with a
// few tweaks....
struct EBRRecord {
uint8_t code[446]; // generally 0s (and we don't care if they aren't)
// First partition entry defines partition; second points to next
// entry in on-disk linked list; remaining two are unused. Note that
// addresses are relative to the extended partition, not to the disk
// as a whole.
struct MBRRecord partitions[4];
uint16_t MBRSignature;
}; // struct EBRRecord
// Possible states of the MBR
enum MBRValidity {invalid, gpt, hybrid, mbr};
// Full data in tweaked MBR format
class MBRData {
protected:
uint8_t code[440];
uint32_t diskSignature;
uint16_t nulls;
struct MBRRecord partitions[4];
uint16_t MBRSignature;
// Above are basic MBR data; now add more stuff....
uint32_t blockSize; // block size (usually 512)
uint64_t diskSize; // size in blocks
char device[256];
// Now an array of partitions for the logicals, in array form (easier
// than a linked list, and good enough for the GPT itself, so....)
struct MBRRecord logicals[NUM_LOGICALS];
MBRValidity state;
struct MBRRecord* GetPartition(int i); // Return primary or logical partition
public:
MBRData(void);
MBRData(char* deviceFilename);
~MBRData(void);
// Pass EmptyMBR 1 to clear the boot loader code, 0 to leave it intact
void EmptyMBR(int clearBootloader = 1);
void SetDiskSize(uint64_t ds) {diskSize = ds;}
int ReadMBRData(char* deviceFilename);
void ReadMBRData(int fd);
int WriteMBRData(void);
void WriteMBRData(int fd);
// ReadLogicalPart() returns last partition # read to logicals[] array,
// or -1 if there was a problem....
int ReadLogicalPart(int fd, uint32_t extendedStart, uint32_t diskOffset,
int partNum);
void DisplayMBRData(void);
void MakeProtectiveMBR(void);
MBRValidity GetValidity(void) {return state;}
void ShowState(void);
void MakePart(int num, uint32_t startLBA, uint32_t lengthLBA, int type = 0x07,
int bootable = 0);
int MakeBiggestPart(int i, int type); // Make partition filling most space
// Functions to find information on free space....
uint32_t FindFirstAvailable(uint32_t start = 1);
uint32_t FindLastInFree(uint32_t start);
// Functions to extract data on specific partitions....
uint8_t GetStatus(int i);
uint8_t GetType(int i);
uint32_t GetFirstSector(int i);
uint32_t GetLength(int i);
}; // struct MBRData
#endif
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