| public GetUShort ( uint offset ) : ushort | ||
| offset | uint | The offset. |
| return | ushort | |
/// <summary>
/// Gets the cluster entry.
/// </summary>
/// <param name="data">The data.</param>
/// <param name="index">The index.</param>
/// <param name="type">The type.</param>
/// <returns></returns>
public static uint GetClusterEntry(byte[] data, uint index, FatType type)
{
BinaryFormat entry = new BinaryFormat(data);
uint cluster = entry.GetUShort(Entry.FirstCluster + (index * Entry.EntrySize));
if (type == FatType.FAT32)
cluster |= ((uint)entry.GetUShort(Entry.EAIndex + (index * Entry.EntrySize))) << 16;
return cluster;
}
/// <summary>
/// Sets the cluster entry value.
/// </summary>
/// <param name="cluster">The cluster.</param>
/// <param name="nextcluster">The nextcluster.</param>
/// <returns></returns>
protected bool SetClusterEntryValue(uint cluster, uint nextcluster)
{
uint fatOffset = 0;
if (fatType == FatType.FAT12)
fatOffset = (cluster + (cluster / 2));
else if (fatType == FatType.FAT16)
fatOffset = cluster * 2;
else //if (type == FatType.FAT32)
fatOffset = cluster * 4;
uint sector = reservedSectors + (fatOffset / bytesPerSector);
uint sectorOffset = fatOffset % bytesPerSector;
uint nbrSectors = 1;
if ((fatType == FatType.FAT12) && (sectorOffset == bytesPerSector - 1))
nbrSectors = 2;
BinaryFormat fat = new BinaryFormat(partition.ReadBlock(sector, nbrSectors));
if (fatType == FatType.FAT12)
{
uint clustervalue = fat.GetUShort(sectorOffset);
if (cluster % 2 == 1)
clustervalue = ((clustervalue & 0x000F) | (nextcluster << 4));
else
clustervalue = ((clustervalue & 0xF000) | (nextcluster & 0x0FFF));
fat.SetUShort(sectorOffset, (ushort)clustervalue);
}
else if (fatType == FatType.FAT16)
fat.SetUShort(sectorOffset, (ushort)(nextcluster & 0xFFFF));
else //if (type == FatType.FAT32)
fat.SetUInt(sectorOffset, nextcluster);
partition.WriteBlock(sector, nbrSectors, fat.Data);
return true;
}
/// <summary>
/// Reads the boot sector.
/// </summary>
/// <returns></returns>
protected bool ReadBootSector()
{
valid = false;
if (blockSize != 512) // only going to work with 512 sector sizes (for now)
return false;
BinaryFormat bootSector = new BinaryFormat(partition.ReadBlock(0, 1));
if (bootSector.GetUShort(BootSector.BootSectorSignature) != 0xAA55)
return false;
byte extendedBootSignature = bootSector.GetByte(BootSector.ExtendedBootSignature);
byte extendedBootSignature32 = bootSector.GetByte(BootSector.FAT32_ExtendedBootSignature);
if ((extendedBootSignature != 0x29) && (extendedBootSignature != 0x28) && (extendedBootSignature32 != 0x29))
return false;
volumeLabel = bootSector.GetString(BootSector.VolumeLabel, 8).ToString().TrimEnd();
bytesPerSector = bootSector.GetUShort(BootSector.BytesPerSector);
sectorsPerCluster = bootSector.GetByte(BootSector.SectorsPerCluster);
reservedSectors = bootSector.GetByte(BootSector.ReservedSectors);
nbrFats = bootSector.GetByte(BootSector.FatAllocationTables);
rootEntries = bootSector.GetUShort(BootSector.MaxRootDirEntries);
rootCluster32 = bootSector.GetUInt(BootSector.FAT32_ClusterNumberOfRoot);
uint sectorsPerFat16 = bootSector.GetUShort(BootSector.SectorsPerFAT);
uint sectorsPerFat32 = bootSector.GetUInt(BootSector.FAT32_SectorPerFAT);
uint totalSectors16 = bootSector.GetUShort(BootSector.TotalSectors16);
uint totalSectors32 = bootSector.GetUInt(BootSector.TotalSectors32);
uint sectorsPerFat = (sectorsPerFat16 != 0) ? sectorsPerFat16 : sectorsPerFat32;
uint fatSectors = 0;
try
{
fatSectors = nbrFats * sectorsPerFat;
clusterSizeInBytes = sectorsPerCluster * blockSize;
rootDirSectors = (((rootEntries * 32) + (bytesPerSector - 1)) / bytesPerSector);
firstDataSector = reservedSectors + (nbrFats * sectorsPerFat) + rootDirSectors;
totalSectors = (totalSectors16 != 0) ? totalSectors16 : totalSectors32;
dataSectors = totalSectors - (reservedSectors + (nbrFats * sectorsPerFat) + rootDirSectors);
totalClusters = dataSectors / sectorsPerCluster;
entriesPerSector = (bytesPerSector / 32);
firstRootDirectorySector = reservedSectors + fatSectors;
dataAreaStart = firstRootDirectorySector + rootDirSectors;
}
catch
{
return false;
}
// Some basic checks
if ((nbrFats == 0) || (nbrFats > 2) || (totalSectors == 0) || (sectorsPerFat == 0))
return false;
if (totalClusters < 4085)
fatType = FatType.FAT12;
else if (totalClusters < 65525)
fatType = FatType.FAT16;
else
fatType = FatType.FAT32;
if (fatType == FatType.FAT12)
{
reservedClusterMark = 0xFF0;
endOfClusterMark = 0x0FF8;
badClusterMark = 0x0FF7;
fatMask = 0xFFFFFFFF;
fatEntries = sectorsPerFat * 3 * blockSize / 2;
}
else if (fatType == FatType.FAT16)
{
reservedClusterMark = 0xFFF0;
endOfClusterMark = 0xFFF8;
badClusterMark = 0xFFF7;
fatMask = 0xFFFFFFFF;
fatEntries = sectorsPerFat * blockSize / 2;
}
else
{ // if (type == FatType.FAT32) {
reservedClusterMark = 0xFFF0;
endOfClusterMark = 0x0FFFFFF8;
badClusterMark = 0x0FFFFFF7;
fatMask = 0x0FFFFFFF;
fatEntries = sectorsPerFat * blockSize / 4;
}
// More basic checks
if ((fatType == FatType.FAT32) && (rootCluster32 == 0))
return false;
valid = true;
serialNbr = bootSector.GetBytes(fatType != FatType.FAT32 ? BootSector.IDSerialNumber : BootSector.FAT32_IDSerialNumber, 4);
return true;
}
/// <summary>
/// Gets the cluster entry value.
/// </summary>
/// <param name="cluster">The cluster.</param>
/// <returns></returns>
protected uint GetClusterEntryValue(uint cluster)
{
uint fatoffset = 0;
if (fatType == FatType.FAT12)
fatoffset = (cluster + (cluster / 2));
else if (fatType == FatType.FAT16)
fatoffset = cluster * 2;
else //if (type == FatType.FAT32)
fatoffset = cluster * 4;
uint sector = reservedSectors + (fatoffset / bytesPerSector);
uint sectorOffset = fatoffset % bytesPerSector;
uint nbrSectors = 1;
if ((fatType == FatType.FAT12) && (sectorOffset == bytesPerSector - 1))
nbrSectors = 2;
BinaryFormat fat = new BinaryFormat(partition.ReadBlock(sector, nbrSectors));
uint clusterValue;
if (fatType == FatType.FAT12)
{
clusterValue = fat.GetUShort(sectorOffset);
if (cluster % 2 == 1)
clusterValue = clusterValue >> 4;
else
clusterValue = clusterValue & 0x0FFF;
}
else if (fatType == FatType.FAT16)
clusterValue = fat.GetUShort(sectorOffset);
else //if (type == FatType.FAT32)
clusterValue = fat.GetUInt(sectorOffset) & 0x0FFFFFFF;
return clusterValue;
}
/// <summary>
/// Reads the LBA48.
/// </summary>
/// <param name="operation">The operation.</param>
/// <param name="drive">The drive.</param>
/// <param name="lba">The lba.</param>
/// <param name="data">The data.</param>
/// <param name="offset">The offset.</param>
/// <returns></returns>
protected bool ReadLBA48(SectorOperation operation, uint drive, uint lba, byte[] data, uint offset)
{
if (drive > MaximunDriveCount)
return false;
FeaturePort.Write8(0);
FeaturePort.Write8(0);
SectorCountPort.Write8(0);
SectorCountPort.Write8(1);
LBALowPort.Write8((byte)((lba >> 24) & 0xFF));
LBALowPort.Write8((byte)(lba & 0xFF));
LBAMidPort.Write8((byte)((lba >> 32) & 0xFF));
LBAMidPort.Write8((byte)((lba >> 8) & 0xFF));
LBAHighPort.Write8((byte)((lba >> 40) & 0xFF));
LBAHighPort.Write8((byte)((lba >> 16) & 0xFF));
DeviceHeadPort.Write8((byte)(0x40 | (drive << 4)));
if (operation == SectorOperation.Write)
CommandPort.Write8(0x34);
else
CommandPort.Write8(0x24);
if (!WaitForRegisterReady())
return false;
var sector = new BinaryFormat(data);
//TODO: Don't use PIO
if (operation == SectorOperation.Read)
{
for (uint index = 0; index < 256; index++)
sector.SetUShort(offset + (index * 2), DataPort.Read16());
}
else
{
for (uint index = 0; index < 256; index++)
DataPort.Write16(sector.GetUShort(offset + (index * 2)));
}
return true;
}
/// <summary>
/// Reads the master boot block.
/// </summary>
/// <returns></returns>
public bool Read()
{
valid = false;
if (diskDevice.BlockSize != 512) return false; // only going to work with 512 sector sizes
if (diskDevice.TotalBlocks < 3) return false;
BinaryFormat masterboot = new BinaryFormat(diskDevice.ReadBlock(0, 1));
if (masterboot.GetUShort(MBR.MBRSignature) != MBRConstant.MBRSignature)
return false;
valid = true;
diskSignature = masterboot.GetUInt(MBR.DiskSignature);
for (uint index = 0; index < MaxMBRPartitions; index++) {
uint offset = MBR.FirstPartition + (index * MBRConstant.PartitionSize);
GenericPartition partition = new GenericPartition(index);
partition.Bootable = masterboot.GetByte(offset + PartitionRecord.Status) == MBRConstant.Bootable;
partition.PartitionType = masterboot.GetByte(offset + PartitionRecord.PartitionType);
partition.StartLBA = masterboot.GetUInt(offset + PartitionRecord.LBA);
partition.TotalBlocks = masterboot.GetUInt(offset + PartitionRecord.Sectors);
Partitions[index] = partition;
}
//TODO: Extended Partitions
code = new byte[MBRConstant.CodeAreaSize];
for (uint index = 0; index < MBRConstant.CodeAreaSize; index++)
code[index] = masterboot.GetByte(index);
return valid;
}
