GPT fdisk 0.5.0

Added several features, including a restructuring of the menu system,
GPT-to-MBR conversion, and the ability to re-read the MBR to generate
a fresh GPT from the current on-disk MBR.

1 files changed, 31 insertions, 31 deletions

diff --git a/mbr.h b/mbr.h
index ff824c5..8f7dfbc 100644
--- a/mbr.h
+++ b/mbr.h
@@ -12,9 +12,12 @@
 #define __MBRSTRUCTS
 
 #define MBR_SIGNATURE UINT16_C(0xAA55)
+#define MAX_HEADS 255        /* numbered 0 - 254 */
+#define MAX_SECSPERTRACK 63  /* numbered 1 - 63 */
+#define MAX_CYLINDERS 1024   /* numbered 0 - 1023 */
 
-// Maximum number of logical partitions supported
-#define NUM_LOGICALS 124
+// Maximum number of MBR partitions
+#define MAX_MBR_PARTS 128
 
 using namespace std;
 
@@ -36,9 +39,10 @@ struct MBRRecord {
    uint32_t lengthLBA;
 }; // struct MBRRecord
 
-// Create a 512-byte data structure into which the MBR can be loaded in one
+// A 512-byte data structure into which the MBR can be loaded in one
 // go, for the benefit of FreeBSD which seems to flake out when loading
-// from block devices in multiples other than the block size....
+// from block devices in multiples other than the block size.
+// Also used when loading logical partitions.
 struct TempMBR {
    uint8_t code[440];
    uint32_t diskSignature;
@@ -47,20 +51,6 @@ struct TempMBR {
    uint16_t MBRSignature;
 }; // struct TempMBR
 
-// 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};
 
@@ -70,45 +60,55 @@ protected:
    uint8_t code[440];
    uint32_t diskSignature;
    uint16_t nulls;
-   struct MBRRecord partitions[4];
+   // MAX_MBR_PARTS defaults to 128. This array holds both the primary and
+   // the logical partitions, to simplify data retrieval for GPT conversions.
+   struct MBRRecord partitions[MAX_MBR_PARTS];
    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
+   uint64_t numHeads; // number of heads, in CHS scheme
+   uint64_t numSecspTrack; // number of sectors per track, in CHS scheme
    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;}
+
+   // File I/O functions...
    int ReadMBRData(char* deviceFilename);
    void ReadMBRData(int fd, int checkBlockSize = 1);
+   int ReadLogicalPart(int fd, uint32_t extendedStart, uint32_t diskOffset,
+                       int partNum);
    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);
+
+   // Display data for user...
    void DisplayMBRData(void);
-   void MakeProtectiveMBR(int clearBoot = 0);
-   MBRValidity GetValidity(void) {return state;}
-   void ShowValidity(void);
    void ShowState(void);
+
+   // Functions that set or get disk metadata (size, CHS geometry, etc.)
+   void SetDiskSize(uint64_t ds) {diskSize = ds;}
+   MBRValidity GetValidity(void) {return state;}
+   void SetHybrid(void) {state = hybrid;} // Set hybrid flag
+   void SetCHSGeom(uint32_t h, uint32_t s);
+   int LBAtoCHS(uint64_t lba, uint8_t * chs); // Convert LBA to CHS
+
+   // Functions to create, delete, or change partitions
+   // Pass EmptyMBR 1 to clear the boot loader code, 0 to leave it intact
+   void EmptyMBR(int clearBootloader = 1);
+   void MakeProtectiveMBR(int clearBoot = 0);
    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
    void DeletePartition(int i);
    int DeleteByLocation(uint64_t start64, uint64_t length64);
    void OptimizeEESize(void);
-   void SetHybrid(void) {state = hybrid;} // Set hybrid flag
 
    // Functions to find information on free space....
    uint32_t FindFirstAvailable(uint32_t start = 1);