public static async Task <LoadSegBlock> Parse(byte[] blockBytes)
{
var blockStream = new MemoryStream(blockBytes);
var identifier = await blockStream.ReadAsciiString(); // Identifier 32 bit word : 'LSEG'
if (!identifier.Equals(BlockIdentifiers.LoadSegBlock))
{
throw new IOException("Invalid load seg block identifier");
}
var size = await blockStream.ReadUInt32(); // Size of the structure for checksums
var checksum = await blockStream.ReadInt32(); // Checksum of the structure
var hostId = await blockStream.ReadUInt32(); // SCSI Target ID of host
var nextLoadSegBlock = await blockStream.ReadInt32(); // block number of the next LoadSegBlock, -1 for last
var calculatedChecksum = await BlockHelper.CalculateChecksum(blockBytes, 8);
if (checksum != calculatedChecksum)
{
throw new IOException("Invalid load seg block checksum");
}
var length = (size - 5) * 4;
var data = new byte[length];
Array.Copy(blockBytes, 5 * 4, data, 0, length);
return(new LoadSegBlock
{
BlockBytes = blockBytes,
Checksum = checksum,
HostId = hostId,
NextLoadSegBlock = nextLoadSegBlock,
Data = data
});
}
public static async Task <IEnumerable <FileSystemHeaderBlock> > Read(
RigidDiskBlock rigidDiskBlock, Stream stream)
{
if (rigidDiskBlock.FileSysHdrList == BlockIdentifiers.EndOfBlock)
{
return(Enumerable.Empty <FileSystemHeaderBlock>());
}
var fileSystemHeaderBlocks = new List <FileSystemHeaderBlock>();
var fileSysHdrList = rigidDiskBlock.FileSysHdrList;
do
{
// calculate file system header block offset
var fileSystemHeaderBlockOffset = rigidDiskBlock.BlockSize * fileSysHdrList;
// seek partition block offset
stream.Seek(fileSystemHeaderBlockOffset, SeekOrigin.Begin);
// read block
var block = await BlockHelper.ReadBlock(stream);
// parse file system header block
var fileSystemHeaderBlock = await Parse(block);
fileSystemHeaderBlocks.Add(fileSystemHeaderBlock);
// get next partition list block and increase partition number
fileSysHdrList = fileSystemHeaderBlock.NextFileSysHeaderBlock;
} while (fileSysHdrList > 0 && fileSysHdrList != BlockIdentifiers.EndOfBlock);
foreach (var fileSystemHeaderBlock in fileSystemHeaderBlocks)
{
fileSystemHeaderBlock.LoadSegBlocks =
await LoadSegBlockReader.Read(rigidDiskBlock, fileSystemHeaderBlock, stream);
}
return(fileSystemHeaderBlocks);
}
public static async Task <RigidDiskBlock> Read(Stream stream)
{
var rdbIndex = 0;
var blockSize = 512;
var rdbLocationLimit = 16;
RigidDiskBlock rigidDiskBlock;
// read rigid disk block from one of the first 15 blocks
do
{
// calculate block offset
var blockOffset = blockSize * rdbIndex;
// seek block offset
stream.Seek(blockOffset, SeekOrigin.Begin);
// read block
var block = await BlockHelper.ReadBlock(stream);
// read rigid disk block
rigidDiskBlock = await Parse(block);
rdbIndex++;
} while (rdbIndex < rdbLocationLimit && rigidDiskBlock == null);
// fail, if rigid disk block is null
if (rigidDiskBlock == null)
{
return(null);
}
rigidDiskBlock.PartitionBlocks = await PartitionBlockReader.Read(rigidDiskBlock, stream);
rigidDiskBlock.BadBlocks = await BadBlockReader.Read(rigidDiskBlock, stream);
return(rigidDiskBlock);
}
public static async Task <BadBlock> Parse(byte[] blockBytes)
{
var blockStream = new MemoryStream(blockBytes);
var identifier = await blockStream.ReadAsciiString(); // Identifier 32 bit word : 'BADB'
if (!identifier.Equals(BlockIdentifiers.BadBlock))
{
throw new IOException("Invalid bad block identifier");
}
await blockStream.ReadUInt32(); // Size of the structure for checksums
var checksum = await blockStream.ReadInt32(); // Checksum of the structure
var hostId = await blockStream.ReadUInt32(); // SCSI Target ID of host, not really used
var nextBadBlock = await blockStream.ReadUInt32(); // next BadBlock block
var calculatedChecksum = await BlockHelper.CalculateChecksum(blockBytes, 8);
if (checksum != calculatedChecksum)
{
throw new IOException("Invalid bad block checksum");
}
var data = await blockStream.ReadBytes(((blockBytes.Length / 4) - 6) / 2);
return(new BadBlock
{
BlockBytes = blockBytes,
Checksum = checksum,
HostId = hostId,
NextBadBlock = nextBadBlock,
Data = data
});
}
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 async Task <FileSystemHeaderBlock> Parse(byte[] blockBytes)
{
var blockStream = new MemoryStream(blockBytes);
var identifier = await blockStream.ReadAsciiString(); // Identifier 32 bit word : 'RDSK'
if (!identifier.Equals(BlockIdentifiers.FileSystemHeaderBlock))
{
throw new IOException("Invalid file system header block identifier");
}
await blockStream.ReadUInt32(); // Size of the structure for checksums
var checksum = await blockStream.ReadInt32(); // Checksum of the structure
var hostId = await blockStream.ReadUInt32(); // SCSI Target ID of host, not really used
var nextFileSysHeaderBlock = await blockStream.ReadUInt32(); // Block number of the next FileSysHeaderBlock
var flags = await blockStream.ReadUInt32(); // Flags
// read reserved, unused word
for (var i = 0; i < 2; i++)
{
await blockStream.ReadBytes(4);
}
var dosType =
await blockStream
.ReadBytes(4); // # Dostype of the file system, file system description: match this with partition environment's DE_DOSTYPE entry
var version = await blockStream.ReadUInt32(); // filesystem version 0x0027001b == 39.27
var patchFlags = await blockStream.ReadUInt32();
var type = await blockStream.ReadUInt32();
var task = await blockStream.ReadUInt32();
var fileSysLock = await blockStream.ReadUInt32();
var handler = await blockStream.ReadUInt32();
var stackSize = await blockStream.ReadUInt32();
var priority = await blockStream.ReadInt32();
var startup = await blockStream.ReadInt32();
var segListBlocks = await blockStream.ReadInt32(); // first of linked list of LoadSegBlocks
var globalVec = await blockStream.ReadInt32();
blockStream.Seek(172, SeekOrigin.Begin);
var fileSystemName = await blockStream.ReadNullTerminatedString();
var calculatedChecksum = await BlockHelper.CalculateChecksum(blockBytes, 8);
if (checksum != calculatedChecksum)
{
throw new IOException("Invalid file system header block checksum");
}
return(new FileSystemHeaderBlock
{
BlockBytes = blockBytes,
Checksum = checksum,
HostId = hostId,
NextFileSysHeaderBlock = nextFileSysHeaderBlock,
Flags = flags,
DosType = dosType,
Version = version,
PatchFlags = patchFlags,
Type = type,
Task = task,
Lock = fileSysLock,
Handler = handler,
StackSize = stackSize,
Priority = priority,
Startup = startup,
SegListBlocks = segListBlocks,
GlobalVec = globalVec,
FileSystemName = fileSystemName
});
}
public static async Task <byte[]> BuildBlock(RigidDiskBlock rigidDiskBlock)
{
var blockStream =
new MemoryStream(rigidDiskBlock.BlockBytes == null || rigidDiskBlock.BlockBytes.Length == 0
? new byte[BlockSize.RigidDiskBlock * 4]
: rigidDiskBlock.BlockBytes);
await blockStream.WriteAsciiString(BlockIdentifiers.RigidDiskBlock);
await blockStream.WriteLittleEndianUInt32(BlockSize.RigidDiskBlock); // size
// skip checksum, calculated when block is built
blockStream.Seek(4, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.HostId); // SCSI Target ID of host, not really used
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.BlockSize); // Size of disk blocks
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.Flags); // RDB Flags
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.BadBlockList); // Bad block list
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.PartitionList); // Partition list
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.FileSysHdrList); // File system header list
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.DriveInitCode); // Drive specific init code
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.BootBlockList); // Amiga OS 4 Boot Blocks
// read reserved, unused word, need to be set to $ffffffff
var reservedBytes = new byte[] { 255, 255, 255, 255 };
for (var i = 0; i < 5; i++)
{
await blockStream.WriteBytes(reservedBytes);
}
// physical drive characteristics
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.Cylinders); // Number of the cylinders of the drive
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.Sectors); // Number of sectors of the drive
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.Heads); // Number of heads of the drive
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.Interleave); // Interleave
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.ParkingZone); // Head parking cylinder
// read reserved, unused word, need to be set to $ffffffff
reservedBytes = new byte[4];
for (var i = 0; i < 3; i++)
{
await blockStream.WriteBytes(reservedBytes);
}
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.WritePreComp); // Starting cylinder of write pre-compensation
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.ReducedWrite); // Starting cylinder of reduced write current
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.StepRate); // Step rate of the drive
// read reserved, unused word, need to be set to $ffffffff
for (var i = 0; i < 5; i++)
{
await blockStream.WriteBytes(reservedBytes);
}
// logical drive characteristics
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.RdbBlockLo); // low block of range reserved for hardblocks
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.RdbBlockHi); // high block of range for these hardblocks
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.LoCylinder); // low cylinder of partitionable disk area
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.HiCylinder); // high cylinder of partitionable data area
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.CylBlocks); // number of blocks available per cylinder
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock.AutoParkSeconds); // zero for no auto park
await blockStream.WriteLittleEndianUInt32(rigidDiskBlock
.HighRsdkBlock); // highest block used by RDSK (not including replacement bad blocks)
await blockStream.WriteBytes(reservedBytes); // read reserved, unused word
// drive identification
await blockStream.WriteString(rigidDiskBlock.DiskVendor, 8, 32);
await blockStream.WriteString(rigidDiskBlock.DiskProduct, 16, 32);
await blockStream.WriteString(rigidDiskBlock.DiskRevision, 4, 32);
// write controller vendor
if (!string.IsNullOrWhiteSpace(rigidDiskBlock.ControllerVendor))
{
await blockStream.WriteString(rigidDiskBlock.ControllerVendor, 8, 32);
}
else
{
await blockStream.WriteBytes(new byte[8]);
}
// write controller product
if (!string.IsNullOrWhiteSpace(rigidDiskBlock.ControllerProduct))
{
await blockStream.WriteString(rigidDiskBlock.ControllerProduct, 16, 32);
}
else
{
await blockStream.WriteBytes(new byte[16]);
}
// write controller revision
if (!string.IsNullOrWhiteSpace(rigidDiskBlock.ControllerRevision))
{
await blockStream.WriteString(rigidDiskBlock.ControllerRevision, 4, 32);
}
else
{
await blockStream.WriteBytes(new byte[4]);
}
await blockStream.WriteBytes(reservedBytes); // read reserved, unused word
// calculate and update checksum
var blockBytes = blockStream.ToArray();
rigidDiskBlock.Checksum = await BlockHelper.UpdateChecksum(blockBytes, 8);
rigidDiskBlock.BlockBytes = blockBytes;
return(blockBytes);
}
public static async Task WriteBlock(RigidDiskBlock rigidDiskBlock, Stream stream)
{
// update block pointers to maintain rigid disk block structure
BlockHelper.UpdateBlockPointers(rigidDiskBlock);
// seek rigid disk block offset
stream.Seek(rigidDiskBlock.RdbBlockLo * 512, SeekOrigin.Begin);
var rigidDiskBlockBytes = await BuildBlock(rigidDiskBlock);
await stream.WriteBytes(rigidDiskBlockBytes);
if (rigidDiskBlock.PartitionList != BlockIdentifiers.EndOfBlock)
{
// seek partition block index offset
stream.Seek(rigidDiskBlock.PartitionList * 512, SeekOrigin.Begin);
foreach (var partitionBlock in rigidDiskBlock.PartitionBlocks)
{
var partitionBlockBytes = await PartitionBlockWriter.BuildBlock(partitionBlock);
await stream.WriteBytes(partitionBlockBytes);
if (partitionBlock.NextPartitionBlock == BlockIdentifiers.EndOfBlock)
{
break;
}
// seek next partition block index offset
stream.Seek(partitionBlock.NextPartitionBlock * 512, SeekOrigin.Begin);
}
}
if (rigidDiskBlock.FileSysHdrList != BlockIdentifiers.EndOfBlock)
{
// seek file system header block index offset
stream.Seek(rigidDiskBlock.FileSysHdrList * 512, SeekOrigin.Begin);
foreach (var fileSystemHeaderBlock in rigidDiskBlock.FileSystemHeaderBlocks)
{
var fileSystemHeaderBytes = await FileSystemHeaderBlockWriter.BuildBlock(fileSystemHeaderBlock);
await stream.WriteBytes(fileSystemHeaderBytes);
// seek load seg block index offset
stream.Seek(fileSystemHeaderBlock.SegListBlocks * 512, SeekOrigin.Begin);
foreach (var loadSegBlock in fileSystemHeaderBlock.LoadSegBlocks)
{
var loadSegBlockBytes = await LoadSegBlockWriter.BuildBlock(loadSegBlock);
await stream.WriteBytes(loadSegBlockBytes);
if (loadSegBlock.NextLoadSegBlock == -1)
{
break;
}
// seek next load seg block index offset
stream.Seek(loadSegBlock.NextLoadSegBlock * 512, SeekOrigin.Begin);
}
if (fileSystemHeaderBlock.NextFileSysHeaderBlock == BlockIdentifiers.EndOfBlock)
{
break;
}
// seek next file system header block index offset
stream.Seek(fileSystemHeaderBlock.NextFileSysHeaderBlock * 512, SeekOrigin.Begin);
}
}
if (rigidDiskBlock.BadBlockList != BlockIdentifiers.EndOfBlock)
{
// seek bad block index offset
stream.Seek(rigidDiskBlock.BadBlockList * 512, SeekOrigin.Begin);
foreach (var badBlock in rigidDiskBlock.BadBlocks)
{
var badBlockBytes = await BadBlockWriter.BuildBlock(badBlock);
await stream.WriteBytes(badBlockBytes);
if (badBlock.NextBadBlock == BlockIdentifiers.EndOfBlock)
{
break;
}
// seek next bad block index offset
stream.Seek(badBlock.NextBadBlock * 512, SeekOrigin.Begin);
}
}
}
public static async Task <RigidDiskBlock> Parse(byte[] blockBytes)
{
var blockStream = new MemoryStream(blockBytes);
var magic = await blockStream.ReadAsciiString(); // Identifier 32 bit word : 'RDSK'
if (!magic.Equals(BlockIdentifiers.RigidDiskBlock))
{
return(null);
}
await blockStream.ReadUInt32(); // Size of the structure for checksums
var checksum = await blockStream.ReadInt32(); // Checksum of the structure
var hostId = await blockStream.ReadUInt32(); // SCSI Target ID of host, not really used
var blockSize = await blockStream.ReadUInt32(); // Size of disk blocks
var flags = await blockStream.ReadUInt32(); // RDB Flags
var badBlockList = await blockStream.ReadUInt32(); // Bad block list
var partitionList = await blockStream.ReadUInt32(); // Partition list
var fileSysHdrList = await blockStream.ReadUInt32(); // File system header list
var driveInitCode = await blockStream.ReadUInt32(); // Drive specific init code
var bootBlockList = await blockStream.ReadUInt32(); // Amiga OS 4 Boot Blocks
// skip reserved
blockStream.Seek(4 * 5, SeekOrigin.Current);
// physical drive characteristics
var cylinders = await blockStream.ReadUInt32(); // Number of the cylinders of the drive
var sectors = await blockStream.ReadUInt32(); // Number of sectors of the drive
var heads = await blockStream.ReadUInt32(); // Number of heads of the drive
var interleave = await blockStream.ReadUInt32(); // Interleave
var parkingZone = await blockStream.ReadUInt32(); // Head parking cylinder
// skip reserved
blockStream.Seek(4 * 3, SeekOrigin.Current);
var writePreComp = await blockStream.ReadUInt32(); // Starting cylinder of write pre-compensation
var reducedWrite = await blockStream.ReadUInt32(); // Starting cylinder of reduced write current
var stepRate = await blockStream.ReadUInt32(); // Step rate of the drive
// skip reserved
blockStream.Seek(4 * 5, SeekOrigin.Current);
// logical drive characteristics
var rdbBlockLo = await blockStream.ReadUInt32(); // low block of range reserved for hardblocks
var rdbBlockHi = await blockStream.ReadUInt32(); // high block of range for these hardblocks
var loCylinder = await blockStream.ReadUInt32(); // low cylinder of partitionable disk area
var hiCylinder = await blockStream.ReadUInt32(); // high cylinder of partitionable data area
var cylBlocks = await blockStream.ReadUInt32(); // number of blocks available per cylinder
var autoParkSeconds = await blockStream.ReadUInt32(); // zero for no auto park
var highRsdkBlock =
await blockStream.ReadUInt32(); // highest block used by RDSK (not including replacement bad blocks)
// skip reserved
blockStream.Seek(4, SeekOrigin.Current);
// drive identification
var diskVendor = (await blockStream.ReadBytes(8)).ReadNullTerminatedString().Trim();
var diskProduct = (await blockStream.ReadBytes(16)).ReadNullTerminatedString().Trim();
var diskRevision = (await blockStream.ReadBytes(4)).ReadNullTerminatedString().Trim();
var controllerVendor = (await blockStream.ReadBytes(8)).ReadNullTerminatedString().Trim();
var controllerProduct = (await blockStream.ReadBytes(16)).ReadNullTerminatedString().Trim();
var controllerRevision = (await blockStream.ReadBytes(4)).ReadNullTerminatedString().Trim();
// skip reserved
blockStream.Seek(4, SeekOrigin.Current);
// calculate size of disk in bytes
var diskSize = (long)cylinders * heads * sectors * blockSize;
var calculatedChecksum = await BlockHelper.CalculateChecksum(blockBytes, 8);
if (checksum != calculatedChecksum)
{
throw new Exception("Invalid rigid disk block checksum");
}
return(new RigidDiskBlock
{
BlockBytes = blockBytes,
Checksum = checksum,
HostId = hostId,
BlockSize = blockSize,
Flags = flags,
BadBlockList = badBlockList,
PartitionList = partitionList,
FileSysHdrList = fileSysHdrList,
DriveInitCode = driveInitCode,
BootBlockList = bootBlockList,
Cylinders = cylinders,
Sectors = sectors,
Heads = heads,
Interleave = interleave,
ParkingZone = parkingZone,
WritePreComp = writePreComp,
ReducedWrite = reducedWrite,
StepRate = stepRate,
RdbBlockLo = rdbBlockLo,
RdbBlockHi = rdbBlockHi,
LoCylinder = loCylinder,
HiCylinder = hiCylinder,
CylBlocks = cylBlocks,
AutoParkSeconds = autoParkSeconds,
HighRsdkBlock = highRsdkBlock,
DiskVendor = diskVendor,
DiskProduct = diskProduct,
DiskRevision = diskRevision,
ControllerVendor = controllerVendor,
ControllerProduct = controllerProduct,
ControllerRevision = controllerRevision,
DiskSize = diskSize
});
}
public static async Task <PartitionBlock> Parse(RigidDiskBlock rigidDiskBlock, byte[] blockBytes)
{
var blockStream = new MemoryStream(blockBytes);
var magic = await blockStream.ReadAsciiString(); // Identifier 32 bit word : 'PART'
if (!magic.Equals(BlockIdentifiers.PartitionBlock))
{
return(null);
}
await blockStream.ReadUInt32(); // Size of the structure for checksums
var checksum = await blockStream.ReadInt32(); // Checksum of the structure
var hostId = await blockStream.ReadUInt32(); // SCSI Target ID of host, not really used
var nextPartitionBlock = await blockStream.ReadUInt32(); // Block number of the next PartitionBlock
var flags = await blockStream.ReadUInt32(); // Part Flags (NOMOUNT and BOOTABLE)
// skip reserved
blockStream.Seek(4 * 2, SeekOrigin.Current);
var devFlags = await blockStream.ReadUInt32(); // Preferred flags for OpenDevice
var driveNameLength =
(await blockStream.ReadBytes(1)).FirstOrDefault(); // Preferred DOS device name: BSTR form
var driveName = await blockStream.ReadString(driveNameLength); // # Preferred DOS device name: BSTR form
if (driveNameLength < 31)
{
await blockStream.ReadBytes(31 - driveNameLength);
}
// skip reserved
blockStream.Seek(4 * 15, SeekOrigin.Current);
var sizeOfVector = await blockStream.ReadUInt32(); // Size of Environment vector
var sizeBlock = await blockStream.ReadUInt32(); // Size of the blocks in 32 bit words, usually 128
var secOrg = await blockStream.ReadUInt32(); // Not used; must be 0
var surfaces = await blockStream.ReadUInt32(); // Number of heads (surfaces)
var sectors = await blockStream.ReadUInt32(); // Disk sectors per block, used with SizeBlock, usually 1
var blocksPerTrack = await blockStream.ReadUInt32(); // Blocks per track. drive specific
var reserved = await blockStream.ReadUInt32(); // DOS reserved blocks at start of partition.
var preAlloc = await blockStream.ReadUInt32(); // DOS reserved blocks at end of partition
var interleave = await blockStream.ReadUInt32(); // Not used, usually 0
var lowCyl = await blockStream.ReadUInt32(); // First cylinder of the partition
var highCyl = await blockStream.ReadUInt32(); // Last cylinder of the partition
var numBuffer = await blockStream.ReadUInt32(); // Initial # DOS of buffers.
var bufMemType = await blockStream.ReadUInt32(); // Type of mem to allocate for buffers
var maxTransfer = await blockStream.ReadUInt32(); // Max number of bytes to transfer at a time
var mask = await blockStream.ReadUInt32(); // Address Mask to block out certain memory
var bootPriority = await blockStream.ReadUInt32(); // Boot priority for autoboot
var dosType = await blockStream.ReadBytes(4); // # Dostype of the file system
var baud = await blockStream.ReadUInt32(); // Baud rate for serial handler
var control = await blockStream.ReadUInt32(); // Control word for handler/filesystem
var bootBlocks = await blockStream.ReadUInt32(); // Number of blocks containing boot code
// skip reserved
blockStream.Seek(4 * 12, SeekOrigin.Current);
// calculate size of partition in bytes
var partitionSize = (long)(highCyl - lowCyl + 1) * surfaces * blocksPerTrack * rigidDiskBlock.BlockSize;
var calculatedChecksum = await BlockHelper.CalculateChecksum(blockBytes, 8);
if (checksum != calculatedChecksum)
{
throw new Exception("Invalid partition block checksum");
}
var fileSystemBlockSize = sizeBlock * 4;
return(new PartitionBlock
{
BlockBytes = blockBytes,
Checksum = checksum,
HostId = hostId,
NextPartitionBlock = nextPartitionBlock,
Flags = flags,
DevFlags = devFlags,
DriveName = driveName,
SizeOfVector = sizeOfVector,
SizeBlock = sizeBlock,
SecOrg = secOrg,
Surfaces = surfaces,
Sectors = sectors,
BlocksPerTrack = blocksPerTrack,
Reserved = reserved,
PreAlloc = preAlloc,
Interleave = interleave,
LowCyl = lowCyl,
HighCyl = highCyl,
NumBuffer = numBuffer,
BufMemType = bufMemType,
MaxTransfer = maxTransfer,
Mask = mask,
BootPriority = bootPriority,
DosType = dosType,
Baud = baud,
Control = control,
BootBlocks = bootBlocks,
PartitionSize = partitionSize,
FileSystemBlockSize = fileSystemBlockSize,
});
}
public static async Task <byte[]> BuildBlock(FileSystemHeaderBlock fileSystemHeaderBlock)
{
var blockStream =
new MemoryStream(
fileSystemHeaderBlock.BlockBytes == null || fileSystemHeaderBlock.BlockBytes.Length == 0
? new byte[BlockSize.FileSystemHeaderBlock * 4]
: fileSystemHeaderBlock.BlockBytes);
await blockStream.WriteAsciiString(BlockIdentifiers.FileSystemHeaderBlock);
await blockStream.WriteLittleEndianUInt32(BlockSize.FileSystemHeaderBlock); // size
// skip checksum, calculated when block is built
blockStream.Seek(4, SeekOrigin.Current);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock
.HostId); // SCSI Target ID of host, not really used
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock
.NextFileSysHeaderBlock); // Block number of the next FileSysHeaderBlock
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.Flags); // Flags
// skip reserved
blockStream.Seek(4 * 2, SeekOrigin.Current);
await blockStream
.WriteBytes(fileSystemHeaderBlock
.DosType); // # Dostype of the file system, file system description: match this with partition environment's DE_DOSTYPE entry
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock
.Version); // filesystem version 0x0027001b == 39.27
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.PatchFlags);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.Type);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.Task);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.Lock);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.Handler);
await blockStream.WriteLittleEndianUInt32(fileSystemHeaderBlock.StackSize);
await blockStream.WriteLittleEndianInt32(fileSystemHeaderBlock.Priority);
await blockStream.WriteLittleEndianInt32(fileSystemHeaderBlock.Startup);
await blockStream.WriteLittleEndianInt32(fileSystemHeaderBlock
.SegListBlocks); // first of linked list of LoadSegBlocks
await blockStream.WriteLittleEndianInt32(fileSystemHeaderBlock.GlobalVec);
// skip reserved
blockStream.Seek((23 + 21) * 4, SeekOrigin.Current);
// calculate and update checksum
var blockBytes = blockStream.ToArray();
fileSystemHeaderBlock.Checksum = await BlockHelper.UpdateChecksum(blockBytes, 8);
fileSystemHeaderBlock.BlockBytes = blockBytes;
return(blockBytes);
}
