private void WriteRecord(int i, BiosPartitionRecord newRecord)
{
_diskData.Position = 0;
byte[] bootSector = Utilities.ReadFully(_diskData, Utilities.SectorSize);
newRecord.WriteTo(bootSector, 0x01BE + (i * 16));
_diskData.Position = 0;
_diskData.Write(bootSector, 0, bootSector.Length);
}
private static BiosPartitionRecord[] ReadPrimaryRecords(byte[] bootSector)
{
BiosPartitionRecord[] records = new BiosPartitionRecord[4];
for (int i = 0; i < 4; ++i)
{
records[i] = new BiosPartitionRecord(bootSector, 0x01BE + (i * 0x10), 0, i);
}
return(records);
}
/// <summary>
/// Updates the CHS fields in partition records to reflect a new BIOS geometry.
/// </summary>
/// <param name="geometry">The disk's new BIOS geometry</param>
/// <remarks>The partitions are not relocated to a cylinder boundary, just the CHS fields are updated on the
/// assumption the LBA fields are definitive.</remarks>
public void UpdateBiosGeometry(Geometry geometry)
{
_diskData.Position = 0;
byte[] bootSector = Utilities.ReadFully(_diskData, Utilities.SectorSize);
BiosPartitionRecord[] records = ReadPrimaryRecords(bootSector);
for (int i = 0; i < records.Length; ++i)
{
BiosPartitionRecord record = records[i];
if (record.IsValid)
{
ChsAddress newStartAddress = geometry.ToChsAddress(record.LBAStartAbsolute);
if (newStartAddress.Cylinder > 1023)
{
newStartAddress = new ChsAddress(1023, geometry.HeadsPerCylinder - 1, geometry.SectorsPerTrack);
}
ChsAddress newEndAddress = geometry.ToChsAddress(record.LBAStartAbsolute + record.LBALength - 1);
if (newEndAddress.Cylinder > 1023)
{
newEndAddress = new ChsAddress(1023, geometry.HeadsPerCylinder - 1, geometry.SectorsPerTrack);
}
record.StartCylinder = (ushort)newStartAddress.Cylinder;
record.StartHead = (byte)newStartAddress.Head;
record.StartSector = (byte)newStartAddress.Sector;
record.EndCylinder = (ushort)newEndAddress.Cylinder;
record.EndHead = (byte)newEndAddress.Head;
record.EndSector = (byte)newEndAddress.Sector;
WriteRecord(i, record);
}
}
_diskGeometry = geometry;
}
internal BiosPartitionInfo(BiosPartitionTable table, BiosPartitionRecord record)
{
_table = table;
_record = record;
}
private BiosPartitionRecord[] GetExtendedRecords(BiosPartitionRecord r)
{
return(new BiosExtendedPartitionTable(_diskData, r.LBAStart).GetPartitions());
}
private static bool IsExtendedPartition(BiosPartitionRecord r)
{
return(r.PartitionType == BiosPartitionTypes.Extended || r.PartitionType == BiosPartitionTypes.ExtendedLba);
}
internal SparseStream Open(BiosPartitionRecord record)
{
return(new SubStream(_diskData, Ownership.None, ((long)record.LBAStartAbsolute) * Utilities.SectorSize, ((long)record.LBALength) * Utilities.SectorSize));
}
/// <summary>
/// Creates a new Primary Partition, specified by Logical Block Addresses.
/// </summary>
/// <param name="first">The LBA address of the first sector (inclusive)</param>
/// <param name="last">The LBA address of the last sector (inclusive)</param>
/// <param name="type">The BIOS (MBR) type of the new partition</param>
/// <param name="markActive">Whether to mark the partition active (bootable)</param>
/// <returns>The index of the new partition</returns>
public int CreatePrimaryBySector(long first, long last, byte type, bool markActive)
{
if (first >= last)
{
throw new ArgumentException("The first sector in a partition must be before the last");
}
if ((last + 1) * _diskGeometry.BytesPerSector > _diskData.Length)
{
throw new ArgumentOutOfRangeException("last", last, "The last sector extends beyond the end of the disk");
}
BiosPartitionRecord[] existing = GetPrimaryRecords();
BiosPartitionRecord newRecord = new BiosPartitionRecord();
ChsAddress startAddr = _diskGeometry.ToChsAddress(first);
ChsAddress endAddr = _diskGeometry.ToChsAddress(last);
// Because C/H/S addresses can max out at lower values than the LBA values,
// the special tuple (1023, 254, 63) is used.
if (startAddr.Cylinder > 1023)
{
startAddr = new ChsAddress(1023, 254, 63);
}
if (endAddr.Cylinder > 1023)
{
endAddr = new ChsAddress(1023, 254, 63);
}
newRecord.StartCylinder = (ushort)startAddr.Cylinder;
newRecord.StartHead = (byte)startAddr.Head;
newRecord.StartSector = (byte)startAddr.Sector;
newRecord.EndCylinder = (ushort)endAddr.Cylinder;
newRecord.EndHead = (byte)endAddr.Head;
newRecord.EndSector = (byte)endAddr.Sector;
newRecord.LBAStart = (uint)first;
newRecord.LBALength = (uint)(last - first + 1);
newRecord.PartitionType = type;
newRecord.Status = (byte)(markActive ? 0x80 : 0x00);
// First check for overlap with existing partition...
foreach (var r in existing)
{
if (Utilities.RangesOverlap((uint)first, (uint)last + 1, r.LBAStartAbsolute, r.LBAStartAbsolute + r.LBALength))
{
throw new IOException("New partition overlaps with existing partition");
}
}
// Now look for empty partition
for (int i = 0; i < 4; ++i)
{
if (!existing[i].IsValid)
{
WriteRecord(i, newRecord);
return(i);
}
}
throw new IOException("No primary partition slots available");
}
