private void InitBootSector(BootSector bs) { bs.Init(); bs.SetFileSystemTypeLabel(fatType.GetLabel()); bs.SetNrReservedSectors(reservedSectors); bs.SetNrFats(fatCount); bs.SetSectorsPerCluster(sectorsPerCluster); bs.SetMediumDescriptor(MEDIUM_DESCRIPTOR_HD); bs.SetSectorsPerTrack(DEFAULT_SECTORS_PER_TRACK); bs.SetNrHeads(DEFAULT_HEADS); bs.SetOemName(oemName); }
private Fat(BootSector bs, long offset) { this.bs = bs; fatType = bs.GetFatType(); if (bs.GetSectorsPerFat() > int.MaxValue) { throw new ArgumentException("FAT too large"); } if (bs.GetSectorsPerFat() <= 0) { throw new IOException( "boot sector says there are " + bs.GetSectorsPerFat() + " sectors per FAT"); } if (bs.GetBytesPerSector() <= 0) { throw new IOException( "boot sector says there are " + bs.GetBytesPerSector() + " bytes per sector"); } sectorCount = (int)bs.GetSectorsPerFat(); sectorSize = bs.GetBytesPerSector(); device = bs.GetDevice(); this.offset = offset; lastAllocatedCluster = FIRST_CLUSTER; if (bs.GetDataClusterCount() > int.MaxValue) { throw new IOException("too many data clusters"); } if (bs.GetDataClusterCount() == 0) { throw new IOException("no data clusters"); } lastClusterIndex = (int)bs.GetDataClusterCount() + FIRST_CLUSTER; entries = new long[(int)((sectorCount * sectorSize) / fatType.GetEntrySize())]; if (lastClusterIndex > entries.Length) { throw new IOException( "file system has " + lastClusterIndex + "clusters but only " + entries.Length + " FAT entries"); } }
/// <summary> /// Constructor for FatFileSystem in specified readOnly mode /// </summary> /// <param name="device">the <see cref="IBlockDevice"/> holding the file system</param> /// <param name="readOnly"></param> /// <param name="ignoreFatDifferences"></param> /// <exception cref="IOException">IOException on read error</exception> private FatFileSystem(IBlockDevice device, bool readOnly, bool ignoreFatDifferences) : base(readOnly) { bs = BootSector.Read(device); if (bs.GetNrFats() <= 0) { throw new IOException( "boot sector says there are no FATs"); } filesOffset = FatUtils.GetFilesOffset(bs); fatType = bs.GetFatType(); fat = Fat.Read(bs, 0); if (!ignoreFatDifferences) { for (var i = 1; i < bs.GetNrFats(); i++) { var tmpFat = Fat.Read(bs, i); if (!fat.Equals(tmpFat)) { throw new IOException("FAT " + i + " differs from FAT 0"); } } } if (fatType == FatType.BaseFat32) { var f32Bs = (Fat32BootSector)bs; var rootDirFile = new ClusterChain(fat, f32Bs.GetRootDirFirstCluster(), IsReadOnly()); rootDirStore = ClusterChainDirectory.ReadRoot(rootDirFile); fsiSector = FsInfoSector.Read(f32Bs); if (fsiSector.GetFreeClusterCount() != fat.GetFreeClusterCount()) { throw new IOException("free cluster count mismatch - fat: " + fat.GetFreeClusterCount() + " - fsinfo: " + fsiSector.GetFreeClusterCount()); } } else { rootDirStore = Fat16RootDirectory.Read((Fat16BootSector)bs, readOnly); fsiSector = null; } rootDir = new FatLfnDirectory(rootDirStore, fat, IsReadOnly()); }
/// <summary> /// Reads a <see cref="Fat"/> as specified by a <see cref="BootSector"/>. /// </summary> /// <param name="bs">the boot sector specifying the <see cref="Fat"/> layout</param> /// <param name="fatNr">the number of the <see cref="Fat"/> to read</param> /// <returns>the <see cref="Fat"/> that was read</returns> /// <exception cref="IOException">IOException on read error</exception> /// <exception cref="ArgumentException">ArgumentException if fatNr is greater than /// <see cref="BootSector.GetNrFats"/></exception> public static Fat Read(BootSector bs, int fatNr) { if (fatNr > bs.GetNrFats()) { throw new ArgumentException( "boot sector says there are only " + bs.GetNrFats() + " FATs when reading FAT #" + fatNr); } var fatOffset = FatUtils.GetFatOffset(bs, fatNr); var result = new Fat(bs, fatOffset); result.Read(); return(result); }
/// <summary> /// Creates a new <see cref="Fat"/> as specified by a <see cref="BootSector"/>. /// </summary> /// <param name="bs">the boot sector specifying the <see cref="Fat"/> layout</param> /// <param name="fatNr">the number of the <see cref="Fat"/> to create</param> /// <returns>the <see cref="Fat"/> that was created</returns> /// <exception cref="IOException">IOException on write error</exception> /// <exception cref="ArgumentException">ArgumentException if fatNr is greater than /// <see cref="BootSector.GetNrFats"/></exception> public static Fat Create(BootSector bs, int fatNr) { if (fatNr > bs.GetNrFats()) { throw new ArgumentException( "boot sector says there are only " + bs.GetNrFats() + " FATs when creating FAT #" + fatNr); } var fatOffset = FatUtils.GetFatOffset(bs, fatNr); var result = new Fat(bs, fatOffset); if (bs.GetDataClusterCount() > result.entries.Length) { throw new IOException("FAT too small for device"); } result.Init(bs.GetMediumDescriptor()); result.Write(); return(result); }