public static PartitionBlock Create(RigidDiskBlock rigidDiskBlock, byte[] dosType, string driveName, long size = 0, bool bootable = false)
{
var lastPartitionBlock = rigidDiskBlock.PartitionBlocks.LastOrDefault();
var lowCyl = lastPartitionBlock == null ? rigidDiskBlock.LoCylinder : lastPartitionBlock.HighCyl + 1;
uint cylinders;
if (size > 0)
{
size = size.ToSectorSize();
var blocksPerCylinder = rigidDiskBlock.Heads * rigidDiskBlock.Sectors;
cylinders = (uint)Math.Floor((double)size / (blocksPerCylinder * rigidDiskBlock.BlockSize));
}
else
{
cylinders = lastPartitionBlock == null
? rigidDiskBlock.Cylinders
: rigidDiskBlock.Cylinders - lowCyl;
}
var highCyl = lowCyl + cylinders - 1 > rigidDiskBlock.HiCylinder
? rigidDiskBlock.HiCylinder
: lowCyl + cylinders - 1;
var partitionBlock = new PartitionBlock
{
PartitionSize = cylinders * rigidDiskBlock.Heads * rigidDiskBlock.Sectors * rigidDiskBlock.BlockSize,
DosType = dosType,
DriveName = driveName,
Flags = bootable ? (uint)PartitionFlagsEnum.Bootable : 0,
LowCyl = lowCyl,
HighCyl = highCyl
};
return(partitionBlock);
}
public static async Task <byte[]> BuildBlock(PartitionBlock partitionBlock)
{
var blockStream =
new MemoryStream(partitionBlock.BlockBytes == null || partitionBlock.BlockBytes.Length == 0
? new byte[BlockSize.PartitionBlock * 4]
: partitionBlock.BlockBytes);
await blockStream.WriteAsciiString(BlockIdentifiers.PartitionBlock);
await blockStream.WriteLittleEndianUInt32(BlockSize.PartitionBlock); // size
// skip checksum, calculated when block is built
blockStream.Seek(4, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(partitionBlock
.HostId); // SCSI Target ID of host, not really used
await blockStream.WriteLittleEndianUInt32(partitionBlock
.NextPartitionBlock); // Block number of the next PartitionBlock
await blockStream.WriteLittleEndianUInt32(partitionBlock.Flags); // Part Flags (NOMOUNT and BOOTABLE)
// skip reserved
blockStream.Seek(4 * 2, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(partitionBlock.DevFlags); // Preferred flags for OpenDevice
var driveName = partitionBlock.DriveName.Length > 31
? partitionBlock.DriveName.Substring(0, 31)
: partitionBlock.DriveName;
await blockStream.WriteBytes(new[] { Convert.ToByte(driveName.Length) });
await blockStream.WriteString(driveName, 31);
// skip reserved
blockStream.Seek(4 * 15, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(partitionBlock.SizeOfVector); // Size of Environment vector
await blockStream.WriteLittleEndianUInt32(partitionBlock
.SizeBlock); // Size of the blocks in 32 bit words, usually 128
await blockStream.WriteLittleEndianUInt32(partitionBlock.SecOrg); // Not used; must be 0
await blockStream.WriteLittleEndianUInt32(partitionBlock.Surfaces); // Number of heads (surfaces)
await blockStream.WriteLittleEndianUInt32(partitionBlock
.Sectors); // Disk sectors per block, used with SizeBlock, usually 1
await blockStream.WriteLittleEndianUInt32(partitionBlock
.BlocksPerTrack); // Blocks per track. drive specific
await blockStream.WriteLittleEndianUInt32(partitionBlock
.Reserved); // DOS reserved blocks at start of partition.
await blockStream.WriteLittleEndianUInt32(partitionBlock
.PreAlloc); // DOS reserved blocks at end of partition
await blockStream.WriteLittleEndianUInt32(partitionBlock.Interleave); // Not used, usually 0
await blockStream.WriteLittleEndianUInt32(partitionBlock.LowCyl); // First cylinder of the partition
await blockStream.WriteLittleEndianUInt32(partitionBlock.HighCyl); // Last cylinder of the partition
await blockStream.WriteLittleEndianUInt32(partitionBlock.NumBuffer); // Initial # DOS of buffers.
await blockStream.WriteLittleEndianUInt32(partitionBlock.BufMemType); // Type of mem to allocate for buffers
await blockStream.WriteLittleEndianUInt32(partitionBlock
.MaxTransfer); // Max number of bytes to transfer at a time
await blockStream.WriteLittleEndianUInt32(partitionBlock.Mask); // Address Mask to block out certain memory
await blockStream.WriteLittleEndianUInt32(partitionBlock.BootPriority); // Boot priority for autoboot
await blockStream.WriteBytes(partitionBlock.DosType); // # Dostype of the file system
await blockStream.WriteLittleEndianUInt32(partitionBlock.Baud); // Baud rate for serial handler
await blockStream.WriteLittleEndianUInt32(partitionBlock.Control); // Control word for handler/filesystem
await blockStream.WriteLittleEndianUInt32(partitionBlock
.BootBlocks); // Number of blocks containing boot code
// skip reserved
blockStream.Seek(4 * 12, SeekOrigin.Current);
// calculate and update checksum
var blockBytes = blockStream.ToArray();
partitionBlock.Checksum = await BlockHelper.UpdateChecksum(blockBytes, 8);
partitionBlock.BlockBytes = blockBytes;
return(blockBytes);
}
public static void ResetPartitionBlockPointers(PartitionBlock partitionBlock)
{
partitionBlock.NextPartitionBlock = 0;
}
