Files
Aaru/Aaru.Filesystems/FAT/Info.cs

1158 lines
52 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Info.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Microsoft FAT filesystem plugin.
//
// --[ License ] --------------------------------------------------------------
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2025 Natalia Portillo
// ****************************************************************************/
using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using Aaru.Checksums;
using Aaru.CommonTypes.AaruMetadata;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
using Aaru.Logging;
using Marshal = Aaru.Helpers.Marshal;
using Partition = Aaru.CommonTypes.Partition;
namespace Aaru.Filesystems;
public sealed partial class FAT
{
#region IReadOnlyFilesystem Members
/// <inheritdoc />
[SuppressMessage("ReSharper", "JoinDeclarationAndInitializer")]
public bool Identify(IMediaImage imagePlugin, Partition partition)
{
if(2 + partition.Start >= partition.End) return false;
ushort bps;
byte spc;
byte numberOfFats;
ushort reservedSecs;
ushort rootEntries;
ushort sectors;
byte mediaDescriptor;
ushort fatSectors;
uint bigSectors;
byte bpbSignature;
byte fat32Signature;
ulong hugeSectors;
var fat32Id = new byte[8];
var msxId = new byte[6];
byte fatId;
var dosOem = new byte[8];
var atariOem = new byte[6];
ushort bootable = 0;
uint sectorsPerBpb = imagePlugin.Info.SectorSize < 512 ? 512 / imagePlugin.Info.SectorSize : 1;
ErrorNumber errno =
imagePlugin.ReadSectors(0 + partition.Start, false, sectorsPerBpb, out byte[] bpbSector, out _);
if(errno != ErrorNumber.NoError) return false;
errno = imagePlugin.ReadSector(sectorsPerBpb + partition.Start, false, out byte[] fatSector, out _);
if(errno != ErrorNumber.NoError) return false;
HumanParameterBlock humanBpb = Marshal.ByteArrayToStructureBigEndian<HumanParameterBlock>(bpbSector);
ulong expectedClusters = humanBpb.bpc > 0 ? partition.Size / humanBpb.bpc : 0;
AaruLogging.Debug(MODULE_NAME, "Human bpc = {0}", humanBpb.bpc);
AaruLogging.Debug(MODULE_NAME, "Human clusters = {0}", humanBpb.clusters);
AaruLogging.Debug(MODULE_NAME, "Human big_clusters = {0}", humanBpb.big_clusters);
AaruLogging.Debug(MODULE_NAME, "Human expected clusters = {0}", expectedClusters);
// Check clusters for Human68k are correct
bool humanClustersCorrect = humanBpb.clusters == 0
? humanBpb.big_clusters == expectedClusters
: humanBpb.clusters == expectedClusters;
// Check OEM for Human68k is correct
bool humanOemCorrect = bpbSector[2] >= 0x20 &&
bpbSector[3] >= 0x20 &&
bpbSector[4] >= 0x20 &&
bpbSector[5] >= 0x20 &&
bpbSector[6] >= 0x20 &&
bpbSector[7] >= 0x20 &&
bpbSector[8] >= 0x20 &&
bpbSector[9] >= 0x20 &&
bpbSector[10] >= 0x20 &&
bpbSector[11] >= 0x20 &&
bpbSector[12] >= 0x20 &&
bpbSector[13] >= 0x20 &&
bpbSector[14] >= 0x20 &&
bpbSector[15] >= 0x20 &&
bpbSector[16] >= 0x20 &&
bpbSector[17] >= 0x20;
// Check correct branch for Human68k
bool humanBranchCorrect = bpbSector[0] == 0x60 && bpbSector[1] >= 0x20 && bpbSector[1] < 0xFE;
AaruLogging.Debug(MODULE_NAME, "humanClustersCorrect = {0}", humanClustersCorrect);
AaruLogging.Debug(MODULE_NAME, "humanOemCorrect = {0}", humanOemCorrect);
AaruLogging.Debug(MODULE_NAME, "humanBranchCorrect = {0}", humanBranchCorrect);
// If all Human68k checks are correct, it is a Human68k FAT16
if(humanClustersCorrect && humanOemCorrect && humanBranchCorrect && expectedClusters > 0) return true;
Array.Copy(bpbSector, 0x02, atariOem, 0, 6);
Array.Copy(bpbSector, 0x03, dosOem, 0, 8);
bps = BitConverter.ToUInt16(bpbSector, 0x00B);
spc = bpbSector[0x00D];
reservedSecs = BitConverter.ToUInt16(bpbSector, 0x00E);
numberOfFats = bpbSector[0x010];
rootEntries = BitConverter.ToUInt16(bpbSector, 0x011);
sectors = BitConverter.ToUInt16(bpbSector, 0x013);
mediaDescriptor = bpbSector[0x015];
fatSectors = BitConverter.ToUInt16(bpbSector, 0x016);
Array.Copy(bpbSector, 0x052, msxId, 0, 6);
bigSectors = BitConverter.ToUInt32(bpbSector, 0x020);
bpbSignature = bpbSector[0x026];
fat32Signature = bpbSector[0x042];
Array.Copy(bpbSector, 0x052, fat32Id, 0, 8);
hugeSectors = BitConverter.ToUInt64(bpbSector, 0x052);
fatId = fatSector[0];
int bitsInBps = CountBits.Count(bps);
if(imagePlugin.Info.SectorSize >= 512) bootable = BitConverter.ToUInt16(bpbSector, 0x1FE);
bool correctSpc = spc is 1 or 2 or 4 or 8 or 16 or 32 or 64;
string msxString = Encoding.ASCII.GetString(msxId);
string fat32String = Encoding.ASCII.GetString(fat32Id);
bool atariOemCorrect = atariOem[0] >= 0x20 &&
atariOem[1] >= 0x20 &&
atariOem[2] >= 0x20 &&
atariOem[3] >= 0x20 &&
atariOem[4] >= 0x20 &&
atariOem[5] >= 0x20;
bool dosOemCorrect = dosOem[0] >= 0x20 &&
dosOem[1] >= 0x20 &&
dosOem[2] >= 0x20 &&
dosOem[3] >= 0x20 &&
dosOem[4] >= 0x20 &&
dosOem[5] >= 0x20 &&
dosOem[6] >= 0x20 &&
dosOem[7] >= 0x20;
string oemString = Encoding.ASCII.GetString(dosOem);
AaruLogging.Debug(MODULE_NAME, "atari_oem_correct = {0}", atariOemCorrect);
AaruLogging.Debug(MODULE_NAME, "dos_oem_correct = {0}", dosOemCorrect);
AaruLogging.Debug(MODULE_NAME, "bps = {0}", bps);
AaruLogging.Debug(MODULE_NAME, "bits in bps = {0}", bitsInBps);
AaruLogging.Debug(MODULE_NAME, "spc = {0}", spc);
AaruLogging.Debug(MODULE_NAME, "correct_spc = {0}", correctSpc);
AaruLogging.Debug(MODULE_NAME, "reserved_secs = {0}", reservedSecs);
AaruLogging.Debug(MODULE_NAME, "fats_no = {0}", numberOfFats);
AaruLogging.Debug(MODULE_NAME, "root_entries = {0}", rootEntries);
AaruLogging.Debug(MODULE_NAME, "sectors = {0}", sectors);
AaruLogging.Debug(MODULE_NAME, "media_descriptor = 0x{0:X2}", mediaDescriptor);
AaruLogging.Debug(MODULE_NAME, "fat_sectors = {0}", fatSectors);
AaruLogging.Debug(MODULE_NAME, "msx_id = \"{0}\"", msxString);
AaruLogging.Debug(MODULE_NAME, "big_sectors = {0}", bigSectors);
AaruLogging.Debug(MODULE_NAME, "bpb_signature = 0x{0:X2}", bpbSignature);
AaruLogging.Debug(MODULE_NAME, "fat32_signature = 0x{0:X2}", fat32Signature);
AaruLogging.Debug(MODULE_NAME, "fat32_id = \"{0}\"", fat32String);
AaruLogging.Debug(MODULE_NAME, "huge_sectors = {0}", hugeSectors);
AaruLogging.Debug(MODULE_NAME, "fat_id = 0x{0:X2}", fatId);
var apricotBps = BitConverter.ToUInt16(bpbSector, 0x50);
byte apricotSpc = bpbSector[0x52];
var apricotReservedSecs = BitConverter.ToUInt16(bpbSector, 0x53);
byte apricotFatsNo = bpbSector[0x55];
var apricotRootEntries = BitConverter.ToUInt16(bpbSector, 0x56);
var apricotSectors = BitConverter.ToUInt16(bpbSector, 0x58);
byte apricotMediaDescriptor = bpbSector[0x5A];
var apricotFatSectors = BitConverter.ToUInt16(bpbSector, 0x5B);
bool apricotCorrectSpc = apricotSpc is 1 or 2 or 4 or 8 or 16 or 32 or 64;
int bitsInApricotBps = CountBits.Count(apricotBps);
byte apricotPartitions = bpbSector[0x0C];
AaruLogging.Debug(MODULE_NAME, "apricot_bps = {0}", apricotBps);
AaruLogging.Debug(MODULE_NAME, "apricot_spc = {0}", apricotSpc);
AaruLogging.Debug(MODULE_NAME, "apricot_correct_spc = {0}", apricotCorrectSpc);
AaruLogging.Debug(MODULE_NAME, "apricot_reserved_secs = {0}", apricotReservedSecs);
AaruLogging.Debug(MODULE_NAME, "apricot_fats_no = {0}", apricotFatsNo);
AaruLogging.Debug(MODULE_NAME, "apricot_root_entries = {0}", apricotRootEntries);
AaruLogging.Debug(MODULE_NAME, "apricot_sectors = {0}", apricotSectors);
AaruLogging.Debug(MODULE_NAME, "apricot_media_descriptor = 0x{0:X2}", apricotMediaDescriptor);
AaruLogging.Debug(MODULE_NAME, "apricot_fat_sectors = {0}", apricotFatSectors);
// This is to support FAT partitions on hybrid ISO/USB images
if(imagePlugin.Info.MetadataMediaType == MetadataMediaType.OpticalDisc)
{
sectors /= 4;
bigSectors /= 4;
hugeSectors /= 4;
}
switch(oemString)
{
// exFAT
case "EXFAT ":
return false;
// NTFS
case "NTFS " when bootable == 0xAA55 && numberOfFats == 0 && fatSectors == 0:
return false;
// QNX4
case "FQNX4FS ":
return false;
}
// HPFS
if(16 + partition.Start <= partition.End)
{
errno = imagePlugin.ReadSector(16 + partition.Start,
false,
out byte[] hpfsSbSector,
out _); // Seek to superblock, on logical sector 16
if(errno != ErrorNumber.NoError) return false;
var hpfsMagic1 = BitConverter.ToUInt32(hpfsSbSector, 0x000);
var hpfsMagic2 = BitConverter.ToUInt32(hpfsSbSector, 0x004);
if(hpfsMagic1 == 0xF995E849 && hpfsMagic2 == 0xFA53E9C5) return false;
}
switch(bitsInBps)
{
// FAT32 for sure
case 1 when correctSpc &&
numberOfFats <= 2 &&
fatSectors == 0 &&
fat32Signature == 0x29 &&
fat32String == "FAT32 ":
return true;
// short FAT32
case 1 when correctSpc && numberOfFats <= 2 && fatSectors == 0 && fat32Signature == 0x28:
return sectors == 0
? bigSectors == 0
? hugeSectors <= partition.End - partition.Start + 1
: bigSectors <= partition.End - partition.Start + 1
: sectors <= partition.End - partition.Start + 1;
// MSX-DOS FAT12
case 1 when correctSpc &&
numberOfFats <= 2 &&
rootEntries > 0 &&
sectors <= partition.End - partition.Start + 1 &&
fatSectors > 0 &&
msxString == "VOL_ID":
return true;
// EBPB
case 1 when correctSpc &&
numberOfFats <= 2 &&
rootEntries > 0 &&
fatSectors > 0 &&
bpbSignature is 0x28 or 0x29:
return sectors == 0
? bigSectors <= partition.End - partition.Start + 1
: sectors <= partition.End - partition.Start + 1;
// BPB
case 1 when correctSpc &&
reservedSecs < partition.End - partition.Start &&
numberOfFats <= 2 &&
rootEntries > 0 &&
fatSectors > 0:
return sectors == 0
? bigSectors <= partition.End - partition.Start + 1
: sectors <= partition.End - partition.Start + 1;
}
// Apricot BPB
if(bitsInApricotBps == 1 &&
apricotCorrectSpc &&
apricotReservedSecs < partition.End - partition.Start &&
apricotFatsNo <= 2 &&
apricotRootEntries > 0 &&
apricotFatSectors > 0 &&
apricotSectors <= partition.End - partition.Start + 1 &&
apricotPartitions == 0)
return true;
// All FAT12 without BPB can only be used on floppies, without partitions.
if(partition.Start != 0) return false;
// DEC Rainbow, lacks a BPB but has a very concrete structure...
if(imagePlugin.Info is { Sectors: 800, SectorSize: 512 })
{
// DEC Rainbow boots up with a Z80, first byte should be DI (disable interrupts)
byte z80Di = bpbSector[0];
// First FAT1 sector resides at LBA 0x14
errno = imagePlugin.ReadSector(0x14, false, out byte[] fat1Sector0, out _);
if(errno != ErrorNumber.NoError) return false;
// First FAT2 sector resides at LBA 0x1A
errno = imagePlugin.ReadSector(0x1A, false, out byte[] fat2Sector0, out _);
if(errno != ErrorNumber.NoError) return false;
bool equalFatIds = fat1Sector0[0] == fat2Sector0[0] && fat1Sector0[1] == fat2Sector0[1];
// Volume is software interleaved 2:1
var rootMs = new MemoryStream();
foreach(ulong rootSector in new ulong[]
{
0x17, 0x19, 0x1B, 0x1D, 0x1E, 0x20
})
{
errno = imagePlugin.ReadSector(rootSector, false, out byte[] tmp, out _);
if(errno != ErrorNumber.NoError) return false;
rootMs.Write(tmp, 0, tmp.Length);
}
byte[] rootDir = rootMs.ToArray();
var validRootDir = true;
// Iterate all root directory
for(var e = 0; e < 96 * 32; e += 32)
{
for(var c = 0; c < 11; c++)
{
if((rootDir[c + e] >= 0x20 || rootDir[c + e] == 0x00 || rootDir[c + e] == 0x05) &&
rootDir[c + e] != 0xFF &&
rootDir[c + e] != 0x2E)
continue;
validRootDir = false;
break;
}
if(!validRootDir) break;
}
if(z80Di == 0xF3 &&
equalFatIds &&
(fat1Sector0[0] & 0xF0) == 0xF0 &&
fat1Sector0[1] == 0xFF &&
validRootDir)
return true;
}
byte fat2 = fatSector[1];
byte fat3 = fatSector[2];
var fatCluster2 = (ushort)((fat2 << 8) + fat3 & 0xFFF);
AaruLogging.Debug(MODULE_NAME, "1st fat cluster 1 = {0:X3}", fatCluster2);
if(fatCluster2 < 0xFF0) return false;
ulong fat2SectorNo = 0;
switch(fatId)
{
case 0xE5:
if(imagePlugin.Info is { Sectors: 2002, SectorSize: 128 }) fat2SectorNo = 2;
break;
case 0xFD:
switch(imagePlugin.Info.Sectors)
{
case 4004 when imagePlugin.Info.SectorSize == 128:
case 2002 when imagePlugin.Info.SectorSize == 128:
fat2SectorNo = 7;
break;
}
break;
case 0xFE:
fat2SectorNo = imagePlugin.Info.Sectors switch
{
320 when imagePlugin.Info.SectorSize == 512 => 2,
2002 when imagePlugin.Info.SectorSize == 128 => 7,
1232 when imagePlugin.Info.SectorSize == 1024 => 3,
616 when imagePlugin.Info.SectorSize == 1024 => 2,
720 when imagePlugin.Info.SectorSize == 128 => 5,
640 when imagePlugin.Info.SectorSize == 512 => 2,
_ => fat2SectorNo
};
break;
case 0xFF:
if(imagePlugin.Info is { Sectors: 640, SectorSize: 512 }) fat2SectorNo = 2;
break;
default:
if(fatId < 0xE8) return false;
fat2SectorNo = 2;
break;
}
if(fat2SectorNo > partition.End || fat2SectorNo == 0) return false;
AaruLogging.Debug(MODULE_NAME, Localization.Second_fat_starts_at_0, fat2SectorNo);
errno = imagePlugin.ReadSector(fat2SectorNo, false, out byte[] fat2Sector, out _);
if(errno != ErrorNumber.NoError) return false;
fat2 = fat2Sector[1];
fat3 = fat2Sector[2];
fatCluster2 = (ushort)((fat2 << 8) + fat3 & 0xFFF);
if(fatCluster2 < 0xFF0) return false;
return fatId == fat2Sector[0];
}
/// <inheritdoc />
public void GetInformation(IMediaImage imagePlugin, Partition partition, Encoding encoding, out string information,
out FileSystem metadata)
{
encoding ??= Encoding.GetEncoding("IBM437");
information = "";
var sb = new StringBuilder();
metadata = new FileSystem();
uint sectorsPerBpb = imagePlugin.Info.SectorSize < 512 ? 512 / imagePlugin.Info.SectorSize : 1;
ErrorNumber errno =
imagePlugin.ReadSectors(0 + partition.Start, false, sectorsPerBpb, out byte[] bpbSector, out _);
if(errno != ErrorNumber.NoError) return;
BpbKind bpbKind = DetectBpbKind(bpbSector,
imagePlugin,
partition,
out BiosParameterBlockEbpb fakeBpb,
out HumanParameterBlock humanBpb,
out AtariParameterBlock atariBpb,
out byte minBootNearJump,
out bool andosOemCorrect,
out bool bootable);
var isFat12 = false;
var isFat16 = false;
var isFat32 = false;
ulong rootDirectorySector = 0;
string extraInfo = null;
string bootChk = null;
metadata.Bootable = bootable;
// This is needed because for FAT16, GEMDOS increases bytes per sector count instead of using big_sectors field.
uint sectorsPerRealSector;
// This is needed because some OSes don't put volume label as first entry in the root directory
uint sectorsForRootDirectory = 0;
switch(bpbKind)
{
case BpbKind.DecRainbow:
case BpbKind.Hardcoded:
case BpbKind.Msx:
case BpbKind.Apricot:
isFat12 = true;
break;
case BpbKind.ShortFat32:
case BpbKind.LongFat32:
{
isFat32 = true;
Fat32ParameterBlock fat32Bpb = Marshal.ByteArrayToStructureLittleEndian<Fat32ParameterBlock>(bpbSector);
Fat32ParameterBlockShort shortFat32Bpb =
Marshal.ByteArrayToStructureLittleEndian<Fat32ParameterBlockShort>(bpbSector);
// This is to support FAT partitions on hybrid ISO/USB images
if(imagePlugin.Info.MetadataMediaType == MetadataMediaType.OpticalDisc)
{
fat32Bpb.bps *= 4;
fat32Bpb.spc /= 4;
fat32Bpb.big_spfat /= 4;
fat32Bpb.hsectors /= 4;
fat32Bpb.sptrk /= 4;
}
if(fat32Bpb.version != 0)
{
sb.AppendLine(Localization.FAT_Plus);
metadata.Type = FS_TYPE_FAT_PLUS;
}
else
{
sb.AppendLine(Localization.Microsoft_FAT32);
metadata.Type = FS_TYPE_FAT32;
}
if(fat32Bpb.oem_name != null)
{
if(fat32Bpb.oem_name[5] == 0x49 && fat32Bpb.oem_name[6] == 0x48 && fat32Bpb.oem_name[7] == 0x43)
sb.AppendLine(Localization.Volume_has_been_modified_by_Windows_9x_Me_Volume_Tracker);
else
metadata.SystemIdentifier = StringHandlers.CToString(fat32Bpb.oem_name);
}
if(!string.IsNullOrEmpty(metadata.SystemIdentifier))
sb.AppendFormat(Localization.OEM_name_0, metadata.SystemIdentifier.Trim()).AppendLine();
sb.AppendFormat(Localization._0_bytes_per_sector, fat32Bpb.bps).AppendLine();
sb.AppendFormat(Localization._0_sectors_per_cluster, fat32Bpb.spc).AppendLine();
metadata.ClusterSize = (uint)(fat32Bpb.bps * fat32Bpb.spc);
sb.AppendFormat(Localization._0_sectors_reserved_between_BPB_and_FAT, fat32Bpb.rsectors).AppendLine();
if(fat32Bpb is { big_sectors: 0, signature: 0x28 })
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
shortFat32Bpb.huge_sectors,
shortFat32Bpb.huge_sectors * shortFat32Bpb.bps)
.AppendLine();
metadata.Clusters = shortFat32Bpb.huge_sectors / shortFat32Bpb.spc;
}
else if(fat32Bpb.sectors == 0)
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
fat32Bpb.big_sectors,
fat32Bpb.big_sectors * fat32Bpb.bps)
.AppendLine();
metadata.Clusters = fat32Bpb.big_sectors / fat32Bpb.spc;
}
else
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
fat32Bpb.sectors,
fat32Bpb.sectors * fat32Bpb.bps)
.AppendLine();
metadata.Clusters = (ulong)(fat32Bpb.sectors / fat32Bpb.spc);
}
sb.AppendFormat(Localization._0_clusters_on_volume, metadata.Clusters).AppendLine();
sb.AppendFormat(Localization.Media_descriptor_0, fat32Bpb.media).AppendLine();
sb.AppendFormat(Localization._0_sectors_per_FAT, fat32Bpb.big_spfat).AppendLine();
sb.AppendFormat(Localization._0_sectors_per_track, fat32Bpb.sptrk).AppendLine();
sb.AppendFormat(Localization._0_heads, fat32Bpb.heads).AppendLine();
sb.AppendFormat(Localization._0_hidden_sectors_before_BPB, fat32Bpb.hsectors).AppendLine();
sb.AppendFormat(Localization.Cluster_of_root_directory_0, fat32Bpb.root_cluster).AppendLine();
sb.AppendFormat(Localization.Sector_of_FSINFO_structure_0, fat32Bpb.fsinfo_sector).AppendLine();
sb.AppendFormat(Localization.Sector_of_backup_FAT32_parameter_block_0, fat32Bpb.backup_sector)
.AppendLine();
sb.AppendFormat(Localization.Drive_number_0, fat32Bpb.drive_no).AppendLine();
sb.AppendFormat(Localization.Volume_Serial_Number_0, fat32Bpb.serial_no).AppendLine();
metadata.VolumeSerial = $"{fat32Bpb.serial_no:X8}";
if((fat32Bpb.flags & 0xF8) == 0x00)
{
if((fat32Bpb.flags & 0x01) == 0x01)
{
sb.AppendLine(Localization.Volume_should_be_checked_on_next_mount);
metadata.Dirty = true;
}
if((fat32Bpb.flags & 0x02) == 0x02)
sb.AppendLine(Localization.Disk_surface_should_be_checked_on_next_mount);
}
if((fat32Bpb.mirror_flags & 0x80) == 0x80)
{
sb.AppendFormat(Localization.FATs_are_out_of_sync_FAT_0_is_in_use, fat32Bpb.mirror_flags & 0xF)
.AppendLine();
}
else
sb.AppendLine(Localization.All_copies_of_FAT_are_the_same);
if((fat32Bpb.mirror_flags & 0x6F20) == 0x6F20)
sb.AppendLine(Localization.DR_DOS_will_boot_this_FAT32_using_CHS);
else if((fat32Bpb.mirror_flags & 0x4F20) == 0x4F20)
sb.AppendLine(Localization.DR_DOS_will_boot_this_FAT32_using_LBA);
if(fat32Bpb.signature == 0x29)
{
metadata.VolumeName = StringHandlers.SpacePaddedToString(fat32Bpb.volume_label, encoding);
metadata.VolumeName = metadata.VolumeName?.Replace("\0", "");
sb.AppendFormat(Localization.Filesystem_type_0, Encoding.ASCII.GetString(fat32Bpb.fs_type))
.AppendLine();
bootChk = Sha1Context.Data(fat32Bpb.boot_code, out _);
}
else
bootChk = Sha1Context.Data(shortFat32Bpb.boot_code, out _);
// Check that jumps to a correct boot code position and has boot signature set.
// This will mean that the volume will boot, even if just to say "this is not bootable change disk"......
metadata.Bootable =
fat32Bpb.jump[0] == 0xEB && fat32Bpb.jump[1] >= minBootNearJump && fat32Bpb.jump[1] < 0x80 ||
fat32Bpb.jump[0] == 0xE9 &&
fat32Bpb.jump.Length >= 3 &&
BitConverter.ToUInt16(fat32Bpb.jump, 1) >= minBootNearJump &&
BitConverter.ToUInt16(fat32Bpb.jump, 1) <= 0x1FC;
sectorsPerRealSector = fat32Bpb.bps / imagePlugin.Info.SectorSize;
// First root directory sector
rootDirectorySector =
(ulong)((fat32Bpb.root_cluster - 2) * fat32Bpb.spc +
fat32Bpb.big_spfat * fat32Bpb.fats_no +
fat32Bpb.rsectors) *
sectorsPerRealSector;
sectorsForRootDirectory = 1;
if(fat32Bpb.fsinfo_sector + partition.Start <= partition.End)
{
errno = imagePlugin.ReadSector(fat32Bpb.fsinfo_sector + partition.Start,
false,
out byte[] fsinfoSector,
out _);
if(errno != ErrorNumber.NoError) return;
FsInfoSector fsInfo = Marshal.ByteArrayToStructureLittleEndian<FsInfoSector>(fsinfoSector);
if(fsInfo.signature1 == FSINFO_SIGNATURE1 &&
fsInfo is { signature2: FSINFO_SIGNATURE2, signature3: FSINFO_SIGNATURE3 })
{
if(fsInfo.free_clusters < 0xFFFFFFFF)
{
sb.AppendFormat(Localization._0_free_clusters, fsInfo.free_clusters).AppendLine();
metadata.FreeClusters = fsInfo.free_clusters;
}
if(fsInfo.last_cluster is > 2 and < 0xFFFFFFFF)
sb.AppendFormat(Localization.Last_allocated_cluster_0, fsInfo.last_cluster).AppendLine();
}
}
break;
}
// Some fields could overflow fake BPB, those will be handled below
case BpbKind.Atari:
{
ushort sum = 0;
for(var i = 0; i < bpbSector.Length; i += 2) sum += BigEndianBitConverter.ToUInt16(bpbSector, i);
// TODO: Check this
if(sum == 0x1234)
{
metadata.Bootable = true;
var atariSb = new StringBuilder();
atariSb.AppendFormat(Localization.cmdload_will_be_loaded_with_value_0,
BigEndianBitConverter.ToUInt16(bpbSector, 0x01E))
.AppendLine();
atariSb.AppendFormat(Localization.Boot_program_will_be_loaded_at_address_0, atariBpb.ldaaddr)
.AppendLine();
atariSb.AppendFormat(Localization.FAT_and_directory_will_be_cached_at_address_0, atariBpb.fatbuf)
.AppendLine();
if(atariBpb.ldmode == 0)
{
var tmp = new byte[8];
Array.Copy(atariBpb.fname, 0, tmp, 0, 8);
string fname = Encoding.ASCII.GetString(tmp).Trim();
tmp = new byte[3];
Array.Copy(atariBpb.fname, 8, tmp, 0, 3);
string extension = Encoding.ASCII.GetString(tmp).Trim();
string filename;
if(string.IsNullOrEmpty(extension))
filename = fname;
else
filename = fname + "." + extension;
atariSb.AppendFormat(Localization.Boot_program_resides_in_file_0, filename).AppendLine();
}
else
{
atariSb.AppendFormat(Localization.Boot_program_starts_in_sector_0_and_is_1_sectors_long_2_bytes,
atariBpb.ssect,
atariBpb.sectcnt,
atariBpb.sectcnt * atariBpb.bps)
.AppendLine();
}
extraInfo = atariSb.ToString();
}
break;
}
case BpbKind.Human:
metadata.Bootable = true;
break;
}
if(!isFat32)
{
// This is to support FAT partitions on hybrid ISO/USB images
if(imagePlugin.Info.MetadataMediaType == MetadataMediaType.OpticalDisc)
{
fakeBpb.bps *= 4;
fakeBpb.spc /= 4;
fakeBpb.spfat /= 4;
fakeBpb.hsectors /= 4;
fakeBpb.sptrk /= 4;
fakeBpb.rsectors /= 4;
if(fakeBpb.spc == 0) fakeBpb.spc = 1;
}
ulong clusters;
if(bpbKind != BpbKind.Human)
{
int reservedSectors = fakeBpb.rsectors +
fakeBpb.fats_no * fakeBpb.spfat +
fakeBpb.root_ent * 32 / fakeBpb.bps;
if(fakeBpb.sectors == 0)
{
clusters = (ulong)(fakeBpb.spc == 0
? fakeBpb.big_sectors - reservedSectors
: (fakeBpb.big_sectors - reservedSectors) / fakeBpb.spc);
}
else
{
clusters = (ulong)(fakeBpb.spc == 0
? fakeBpb.sectors - reservedSectors
: (fakeBpb.sectors - reservedSectors) / fakeBpb.spc);
}
}
else
clusters = humanBpb.clusters == 0 ? humanBpb.big_clusters : humanBpb.clusters;
// This will walk all the FAT entries and check if they're valid FAT12 or FAT16 entries.
// If the whole table is valid in both senses, it considers the type entry in the BPB.
// BeOS is known to set the type as FAT16 but treat it as FAT12.
if(!isFat12 && !isFat16)
{
if(clusters < 4089)
{
// The first 2 FAT entries do not count as allocation clusters in FAT12 and FAT16
var fat12 = new ushort[clusters + 2];
_reservedSectors = fakeBpb.rsectors;
sectorsPerRealSector = fakeBpb.bps / imagePlugin.Info.SectorSize;
_fatFirstSector = partition.Start + _reservedSectors * sectorsPerRealSector;
errno = imagePlugin.ReadSectors(_fatFirstSector, false, fakeBpb.spfat, out byte[] fatBytes, out _);
if(errno != ErrorNumber.NoError) return;
var pos = 0;
for(var i = 0; i + 3 < fatBytes.Length && pos < fat12.Length; i += 3)
{
fat12[pos++] = (ushort)(((fatBytes[i + 1] & 0xF) << 8) + fatBytes[i + 0]);
if(pos >= fat12.Length) break;
fat12[pos++] = (ushort)(((fatBytes[i + 1] & 0xF0) >> 4) + (fatBytes[i + 2] << 4));
}
bool fat12Valid = fat12[0] >= FAT12_RESERVED && fat12[1] >= FAT12_RESERVED;
if(fat12.Any(entry => entry < FAT12_RESERVED && entry > clusters + 2)) fat12Valid = false;
ushort[] fat16 = MemoryMarshal.Cast<byte, ushort>(fatBytes).ToArray();
bool fat16Valid = fat16[0] >= FAT16_RESERVED && fat16[1] >= 0x3FF0;
if(fat16.Any(entry => entry < FAT16_RESERVED && entry > clusters + 2)) fat16Valid = false;
isFat12 = fat12Valid;
isFat16 = fat16Valid;
// Check BPB type
if(isFat12 == isFat16)
{
isFat12 = fakeBpb.fs_type != null && Encoding.ASCII.GetString(fakeBpb.fs_type) == "FAT12 ";
isFat16 = fakeBpb.fs_type != null && Encoding.ASCII.GetString(fakeBpb.fs_type) == "FAT16 ";
}
if(!isFat12 && !isFat16) isFat12 = true;
}
else
isFat16 = true;
}
if(isFat12)
{
switch(bpbKind)
{
case BpbKind.Atari:
sb.AppendLine(Localization.Atari_FAT12);
break;
case BpbKind.Apricot:
sb.AppendLine(Localization.Apricot_FAT12);
break;
case BpbKind.Human:
sb.AppendLine(Localization.Human68k_FAT12);
break;
default:
sb.AppendLine(Localization.Microsoft_FAT12);
break;
}
metadata.Type = FS_TYPE_FAT12;
}
else if(isFat16)
{
sb.AppendLine(bpbKind switch
{
BpbKind.Atari => Localization.Atari_FAT16,
BpbKind.Human => Localization.Human68k_FAT16,
_ => Localization.Microsoft_FAT16
});
metadata.Type = FS_TYPE_FAT16;
}
if(bpbKind == BpbKind.Atari)
{
if(atariBpb.serial_no[0] == 0x49 && atariBpb.serial_no[1] == 0x48 && atariBpb.serial_no[2] == 0x43)
sb.AppendLine(Localization.Volume_has_been_modified_by_Windows_9x_Me_Volume_Tracker);
else
{
metadata.VolumeSerial = $"{atariBpb.serial_no[0]:X2}{atariBpb.serial_no[1]:X2}{atariBpb.serial_no[2]
:X2}";
}
metadata.SystemIdentifier = StringHandlers.CToString(atariBpb.oem_name);
if(string.IsNullOrEmpty(metadata.SystemIdentifier)) metadata.SystemIdentifier = null;
}
else if(fakeBpb.oem_name != null)
{
if(fakeBpb.oem_name[5] == 0x49 && fakeBpb.oem_name[6] == 0x48 && fakeBpb.oem_name[7] == 0x43)
sb.AppendLine(Localization.Volume_has_been_modified_by_Windows_9x_Me_Volume_Tracker);
else
{
metadata.SystemIdentifier = fakeBpb.oem_name[0] switch
{
// Later versions of Windows create a DOS 3 BPB without OEM name on 8 sectors/track floppies
// OEM ID should be ASCII, otherwise ignore it
>= 0x20 and <= 0x7F when fakeBpb.oem_name[1] >= 0x20 &&
fakeBpb.oem_name[1] <= 0x7F &&
fakeBpb.oem_name[2] >= 0x20 &&
fakeBpb.oem_name[2] <= 0x7F &&
fakeBpb.oem_name[3] >= 0x20 &&
fakeBpb.oem_name[3] <= 0x7F &&
fakeBpb.oem_name[4] >= 0x20 &&
fakeBpb.oem_name[4] <= 0x7F &&
fakeBpb.oem_name[5] >= 0x20 &&
fakeBpb.oem_name[5] <= 0x7F &&
fakeBpb.oem_name[6] >= 0x20 &&
fakeBpb.oem_name[6] <= 0x7F &&
fakeBpb.oem_name[7] >= 0x20 &&
fakeBpb.oem_name[7] <= 0x7F =>
StringHandlers.CToString(fakeBpb.oem_name),
< 0x20 when fakeBpb.oem_name[1] >= 0x20 &&
fakeBpb.oem_name[1] <= 0x7F &&
fakeBpb.oem_name[2] >= 0x20 &&
fakeBpb.oem_name[2] <= 0x7F &&
fakeBpb.oem_name[3] >= 0x20 &&
fakeBpb.oem_name[3] <= 0x7F &&
fakeBpb.oem_name[4] >= 0x20 &&
fakeBpb.oem_name[4] <= 0x7F &&
fakeBpb.oem_name[5] >= 0x20 &&
fakeBpb.oem_name[5] <= 0x7F &&
fakeBpb.oem_name[6] >= 0x20 &&
fakeBpb.oem_name[6] <= 0x7F &&
fakeBpb.oem_name[7] >= 0x20 &&
fakeBpb.oem_name[7] <= 0x7F =>
StringHandlers.CToString(fakeBpb.oem_name, encoding, start: 1),
_ => metadata.SystemIdentifier
};
}
if(fakeBpb.signature is 0x28 or 0x29) metadata.VolumeSerial = $"{fakeBpb.serial_no:X8}";
}
if(metadata.SystemIdentifier != null)
sb.AppendFormat(Localization.OEM_name_0, metadata.SystemIdentifier.Trim()).AppendLine();
sb.AppendFormat(Localization._0_bytes_per_sector, fakeBpb.bps).AppendLine();
if(bpbKind != BpbKind.Human)
{
if(fakeBpb.sectors == 0)
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
fakeBpb.big_sectors,
fakeBpb.big_sectors * fakeBpb.bps)
.AppendLine();
}
else
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
fakeBpb.sectors,
fakeBpb.sectors * fakeBpb.bps)
.AppendLine();
}
}
else
{
sb.AppendFormat(Localization._0_sectors_on_volume_1_bytes,
clusters * humanBpb.bpc / imagePlugin.Info.SectorSize,
clusters * humanBpb.bpc)
.AppendLine();
}
metadata.Clusters = clusters;
sb.AppendFormat(Localization._0_sectors_per_cluster, fakeBpb.spc).AppendLine();
sb.AppendFormat(Localization._0_clusters_on_volume, metadata.Clusters).AppendLine();
metadata.ClusterSize = (uint)(fakeBpb.bps * fakeBpb.spc);
sb.AppendFormat(Localization._0_sectors_reserved_between_BPB_and_FAT, fakeBpb.rsectors).AppendLine();
sb.AppendFormat(Localization._0_FATs, fakeBpb.fats_no).AppendLine();
sb.AppendFormat(Localization._0_entries_in_root_directory, fakeBpb.root_ent).AppendLine();
if(fakeBpb.media > 0) sb.AppendFormat(Localization.Media_descriptor_0, fakeBpb.media).AppendLine();
sb.AppendFormat(Localization._0_sectors_per_FAT, fakeBpb.spfat).AppendLine();
if(fakeBpb.sptrk is > 0 and < 64 && fakeBpb.heads is > 0 and < 256)
{
sb.AppendFormat(Localization._0_sectors_per_track, fakeBpb.sptrk).AppendLine();
sb.AppendFormat(Localization._0_heads, fakeBpb.heads).AppendLine();
}
if(fakeBpb.hsectors <= partition.Start)
sb.AppendFormat(Localization._0_hidden_sectors_before_BPB, fakeBpb.hsectors).AppendLine();
if(fakeBpb.signature is 0x28 or 0x29 || andosOemCorrect)
{
sb.AppendFormat(Localization.Drive_number_0, fakeBpb.drive_no).AppendLine();
if(metadata.VolumeSerial != null)
sb.AppendFormat(Localization.Volume_Serial_Number_0, metadata.VolumeSerial).AppendLine();
if((fakeBpb.flags & 0xF8) == 0x00)
{
if((fakeBpb.flags & 0x01) == 0x01)
{
sb.AppendLine(Localization.Volume_should_be_checked_on_next_mount);
metadata.Dirty = true;
}
if((fakeBpb.flags & 0x02) == 0x02)
sb.AppendLine(Localization.Disk_surface_should_be_checked_on_next_mount);
}
if(fakeBpb.signature == 0x29 || andosOemCorrect)
{
metadata.VolumeName = StringHandlers.SpacePaddedToString(fakeBpb.volume_label, encoding);
metadata.VolumeName = metadata.VolumeName?.Replace("\0", "");
sb.AppendFormat(Localization.Filesystem_type_0, Encoding.ASCII.GetString(fakeBpb.fs_type))
.AppendLine();
}
}
else if(bpbKind == BpbKind.Atari && metadata.VolumeSerial != null)
sb.AppendFormat(Localization.Volume_Serial_Number_0, metadata.VolumeSerial).AppendLine();
bootChk = Sha1Context.Data(fakeBpb.boot_code, out _);
// Workaround that PCExchange jumps into "FAT16 "...
if(metadata.SystemIdentifier == "PCX 2.0 ") fakeBpb.jump[1] += 8;
// Check that jumps to a correct boot code position and has boot signature set.
// This will mean that the volume will boot, even if just to say "this is not bootable change disk"......
if(!metadata.Bootable && fakeBpb.jump != null)
{
metadata.Bootable |=
fakeBpb.jump[0] == 0xEB && fakeBpb.jump[1] >= minBootNearJump && fakeBpb.jump[1] < 0x80 ||
fakeBpb.jump[0] == 0xE9 &&
fakeBpb.jump.Length >= 3 &&
BitConverter.ToUInt16(fakeBpb.jump, 1) >= minBootNearJump &&
BitConverter.ToUInt16(fakeBpb.jump, 1) <= 0x1FC;
}
sectorsPerRealSector = fakeBpb.bps / imagePlugin.Info.SectorSize;
// First root directory sector
rootDirectorySector = (ulong)(fakeBpb.spfat * fakeBpb.fats_no + fakeBpb.rsectors) * sectorsPerRealSector;
sectorsForRootDirectory = (uint)(fakeBpb.root_ent * 32 / imagePlugin.Info.SectorSize);
}
if(extraInfo != null) sb.Append(extraInfo);
if(rootDirectorySector + partition.Start < partition.End &&
imagePlugin.Info.MetadataMediaType != MetadataMediaType.OpticalDisc)
{
errno = imagePlugin.ReadSectors(rootDirectorySector + partition.Start,
false,
sectorsForRootDirectory,
out byte[] rootDirectory,
out _);
if(errno != ErrorNumber.NoError) return;
if(bpbKind == BpbKind.DecRainbow)
{
var rootMs = new MemoryStream();
foreach(ulong rootSector in new ulong[]
{
0x17, 0x19, 0x1B, 0x1D, 0x1E, 0x20
})
{
errno = imagePlugin.ReadSector(rootSector, false, out byte[] tmp, out _);
if(errno != ErrorNumber.NoError) return;
rootMs.Write(tmp, 0, tmp.Length);
}
rootDirectory = rootMs.ToArray();
}
for(var i = 0; i < rootDirectory.Length; i += 32)
{
// Not a correct entry
if(rootDirectory[i] < DIRENT_MIN && rootDirectory[i] != DIRENT_E5) continue;
// Deleted or subdirectory entry
if(rootDirectory[i] == DIRENT_SUBDIR || rootDirectory[i] == DIRENT_DELETED) continue;
// Not a volume label
if(rootDirectory[i + 0x0B] != 0x08 && rootDirectory[i + 0x0B] != 0x28) continue;
DirectoryEntry entry = Marshal.ByteArrayToStructureLittleEndian<DirectoryEntry>(rootDirectory, i, 32);
var fullname = new byte[11];
Array.Copy(entry.filename, 0, fullname, 0, 8);
Array.Copy(entry.extension, 0, fullname, 8, 3);
string volname = encoding.GetString(fullname).Trim();
if(!string.IsNullOrEmpty(volname))
metadata.VolumeName = entry.caseinfo.HasFlag(CaseInfo.AllLowerCase) ? volname.ToLower() : volname;
if(entry is { ctime: > 0, cdate: > 0 })
{
metadata.CreationDate = DateHandlers.DosToDateTime(entry.cdate, entry.ctime);
if(entry.ctime_ms > 0)
metadata.CreationDate = metadata.CreationDate?.AddMilliseconds(entry.ctime_ms * 10);
sb.AppendFormat(Localization.Volume_created_on_0, metadata.CreationDate).AppendLine();
}
if(entry is { mtime: > 0, mdate: > 0 })
{
metadata.ModificationDate = DateHandlers.DosToDateTime(entry.mdate, entry.mtime);
sb.AppendFormat(Localization.Volume_last_modified_on_0, metadata.ModificationDate).AppendLine();
}
if(entry.adate > 0)
{
sb.AppendFormat(Localization.Volume_last_accessed_on_0_d,
DateHandlers.DosToDateTime(entry.adate, 0))
.AppendLine();
}
break;
}
}
if(!string.IsNullOrEmpty(metadata.VolumeName))
sb.AppendFormat(Localization.Volume_label_0, metadata.VolumeName).AppendLine();
if(metadata.Bootable)
{
switch(bpbSector[0])
{
// Intel short jump
case 0xEB when bpbSector[1] < 0x80:
{
int sigSize = bpbSector[510] == 0x55 && bpbSector[511] == 0xAA ? 2 : 0;
var bootCode = new byte[512 - sigSize - bpbSector[1] - 2];
Array.Copy(bpbSector, bpbSector[1] + 2, bootCode, 0, bootCode.Length);
Sha1Context.Data(bootCode, out _);
break;
}
// Intel big jump
case 0xE9 when BitConverter.ToUInt16(bpbSector, 1) < 0x1FC:
{
int sigSize = bpbSector[510] == 0x55 && bpbSector[511] == 0xAA ? 2 : 0;
var bootCode = new byte[512 - sigSize - BitConverter.ToUInt16(bpbSector, 1) - 3];
Array.Copy(bpbSector, BitConverter.ToUInt16(bpbSector, 1) + 3, bootCode, 0, bootCode.Length);
Sha1Context.Data(bootCode, out _);
break;
}
}
sb.AppendLine(Localization.Volume_is_bootable);
sb.AppendFormat(Localization.Boot_code_SHA1_0, bootChk).AppendLine();
string bootName = _knownBootHashes.FirstOrDefault(t => t.hash == bootChk).name;
if(string.IsNullOrWhiteSpace(bootName))
sb.AppendLine(Localization.Unknown_boot_code);
else
sb.AppendFormat(Localization.Boot_code_corresponds_to_0, bootName).AppendLine();
}
information = sb.ToString();
}
#endregion
}