public MBR(BlockDevice device)
{
var aMBR = device.NewBlockArray(1);
device.ReadBlock(0, 1, ref aMBR);
ParsePartition(aMBR, 446);
ParsePartition(aMBR, 462);
ParsePartition(aMBR, 478);
ParsePartition(aMBR, 494);
}
public List<System.FileSystem.Listing.Base> GetRoot()
{
var xResult = new List<System.FileSystem.Listing.Base>();
byte[] xData;
if (FatType == FatTypeEnum.Fat32)
{
xData = NewClusterArray();
ReadCluster(RootCluster, xData);
}
else
{
xData = mDevice.NewBlockArray(RootSectorCount);
mDevice.ReadBlock(RootSector, RootSectorCount, xData);
}
//TODO: Change xLongName to StringBuilder
string xLongName = "";
for (UInt32 i = 0; i < xData.Length; i = i + 32)
{
byte xAttrib = xData[i + 11];
if (xAttrib == Attribs.LongName)
{
byte xType = xData[i + 12];
if (xType == 0)
{
byte xOrd = xData[i];
if ((xOrd & 0x40) > 0)
{
xLongName = "";
}
//TODO: Check LDIR_Ord for ordering and throw exception
// if entries are found out of order.
// Also save buffer and only copy name if a end Ord marker is found.
string xLongPart = xData.GetUtf16String(i + 1, 5);
// We have to check the length because 0xFFFF is a valid Unicode codepoint.
// So we only want to stop if the 0xFFFF is AFTER a 0x0000. We can determin
// this by also looking at the length. Since we short circuit the or, the length
// is rarely evaluated.
if (xData.ToUInt16(i + 14) != 0xFFFF || xLongPart.Length == 5)
{
xLongPart = xLongPart + xData.GetUtf16String(i + 14, 6);
if (xData.ToUInt16(i + 28) != 0xFFFF || xLongPart.Length == 11)
{
xLongPart = xLongPart + xData.GetUtf16String(i + 28, 2);
}
}
xLongName = xLongPart + xLongName;
//TODO: LDIR_Chksum
}
}
else
{
byte xStatus = xData[i];
if (xStatus == 0x00)
{
// Empty slot, and no more entries after this
break;
}
else if (xStatus == 0x05)
{
// Japanese characters - We dont handle these
}
else if (xStatus == 0xE5)
{
// Empty slot, skip it
}
else if (xStatus >= 0x20)
{
string xName;
if (xLongName.Length > 0)
{
// Leading and trailing spaces are to be ignored according to spec.
// Many programs (including Windows) pad trailing spaces although it
// it is not required for long names.
// As per spec, ignore trailing periods
xName = xLongName.Trim();
//If there are trailing periods
int nameIndex = xName.Length - 1;
if (xName[nameIndex] == '.')
{
//Search backwards till we find the first non-period character
for (; nameIndex > 0; nameIndex--)
{
if (xName[nameIndex] != '.')
{
break;
}
}
//Substring to remove the periods
xName = xName.Substring(0, nameIndex + 1);
}
}
else
{
string xEntry = xData.GetAsciiString(i, 11);
xName = xEntry.Substring(0, 8).TrimEnd();
string xExt = xEntry.Substring(8, 3).TrimEnd();
if (xExt.Length > 0)
{
xName = xName + "." + xExt;
}
}
UInt32 xFirstCluster = (UInt32)(xData.ToUInt16(i + 20) << 16 | xData.ToUInt16(i + 26));
var xTest = xAttrib & (Attribs.Directory | Attribs.VolumeID);
if (xTest == 0)
{
UInt32 xSize = xData.ToUInt32(i + 28);
xResult.Add(new Listing.FatFile(this, xName, xSize, xFirstCluster));
}
else if (xTest == Attribs.VolumeID)
{
//
}
else if (xTest == Attribs.Directory)
{
xResult.Add(new Listing.FatDirectory(this, xName));
}
xLongName = "";
}
}
}
return xResult;
}
public FatFileSystem(BlockDevice aDevice)
{
mDevice = aDevice;
byte[] xBPB = mDevice.NewBlockArray(1);
mDevice.ReadBlock(0UL, 1U, xBPB);
UInt16 xSig = xBPB.ToUInt16(510);
if (xSig != 0xAA55)
{
throw new Exception("FAT signature not found.");
}
BytesPerSector = xBPB.ToUInt16(11);
SectorsPerCluster = xBPB[13];
BytesPerCluster = BytesPerSector * SectorsPerCluster;
ReservedSectorCount = xBPB.ToUInt16(14);
NumberOfFATs = xBPB[16];
RootEntryCount = xBPB.ToUInt16(17);
TotalSectorCount = xBPB.ToUInt16(19);
if (TotalSectorCount == 0)
{
TotalSectorCount = xBPB.ToUInt32(32);
}
// FATSz
FatSectorCount = xBPB.ToUInt16(22);
if (FatSectorCount == 0)
{
FatSectorCount = xBPB.ToUInt32(36);
}
//Global.Dbg.Send("FAT Sector Count: " + FatSectorCount);
DataSectorCount = TotalSectorCount - (ReservedSectorCount + (NumberOfFATs * FatSectorCount) + ReservedSectorCount);
// Computation rounds down.
ClusterCount = DataSectorCount / SectorsPerCluster;
// Determine the FAT type. Do not use another method - this IS the official and
// proper way to determine FAT type.
// Comparisons are purposefully < and not <=
// FAT16 starts at 4085, FAT32 starts at 65525
if (ClusterCount < 4085)
{
FatType = FatTypeEnum.Fat12;
}
else if (ClusterCount < 65525)
{
FatType = FatTypeEnum.Fat16;
}
else
{
FatType = FatTypeEnum.Fat32;
}
if (FatType == FatTypeEnum.Fat32)
{
RootCluster = xBPB.ToUInt32(44);
}
else
{
RootSector = ReservedSectorCount + (NumberOfFATs * FatSectorCount);
RootSectorCount = (RootEntryCount * 32 + (BytesPerSector - 1)) / BytesPerSector;
}
DataSector = ReservedSectorCount + (NumberOfFATs * FatSectorCount) + RootSectorCount;
}
public FatFileSystem(Cosmos.HAL.BlockDevice.BlockDevice aDevice)
{
mDevice = aDevice;
byte[] xBPB = mDevice.NewBlockArray(1);
mDevice.ReadBlock(0UL, 1U, xBPB);
UInt16 xSig = xBPB.ToUInt16(510);
if (xSig != 0xAA55)
{
throw new Exception("FAT signature not found.");
}
BytesPerSector = xBPB.ToUInt16(11);
SectorsPerCluster = xBPB[13];
BytesPerCluster = BytesPerSector * SectorsPerCluster;
ReservedSectorCount = xBPB.ToUInt16(14);
NumberOfFATs = xBPB[16];
RootEntryCount = xBPB.ToUInt16(17);
TotalSectorCount = xBPB.ToUInt16(19);
if (TotalSectorCount == 0)
{
TotalSectorCount = xBPB.ToUInt32(32);
}
// FATSz
FatSectorCount = xBPB.ToUInt16(22);
if (FatSectorCount == 0)
{
FatSectorCount = xBPB.ToUInt32(36);
}
//Global.Dbg.Send("FAT Sector Count: " + FatSectorCount);
DataSectorCount = TotalSectorCount - (ReservedSectorCount + (NumberOfFATs * FatSectorCount) + ReservedSectorCount);
// Computation rounds down.
ClusterCount = DataSectorCount / SectorsPerCluster;
// Determine the FAT type. Do not use another method - this IS the official and
// proper way to determine FAT type.
// Comparisons are purposefully < and not <=
// FAT16 starts at 4085, FAT32 starts at 65525
if (ClusterCount < 4085)
{
FatType = FatTypeEnum.Fat12;
}
else if (ClusterCount < 65525)
{
FatType = FatTypeEnum.Fat16;
}
else
{
FatType = FatTypeEnum.Fat32;
}
if (FatType == FatTypeEnum.Fat32)
{
RootCluster = xBPB.ToUInt32(44);
}
else
{
RootSector = ReservedSectorCount + (NumberOfFATs * FatSectorCount);
RootSectorCount = (RootEntryCount * 32 + (BytesPerSector - 1)) / BytesPerSector;
}
DataSector = ReservedSectorCount + (NumberOfFATs * FatSectorCount) + RootSectorCount;
}