patterns: Added very basic MBR and FAT32 filesystem pattern

README.md

@@ -32,6 +32,7 @@ Hex patterns, include patterns and magic files for the use with the ImHex Hex Ed
 | VDF | | `patterns/vdf.hexpat` | Binary Value Data Format (.vdf) files | 
 | IP | | `patterns/ip.hexpat` | Ethernet II Frames (IP Packets) | 
 | UF2 | | `patterns/uf2.hexpat` | [USB Flashing Format](https://github.com/microsoft/uf2) | 
+| File System | | `patterns/fs.hexpat` | Drive File System | 
 
 ### Scripts
 

patterns/fs.hexpat

@@ -0,0 +1,168 @@
+#include <std/io.pat>
+
+struct DiskTimeStamp {
+	u8 seconds, minutes, hours;
+};
+
+enum DiskProtection : u16 {
+	None = 0x0000,
+	CopyProtected = 0x5A5A
+};
+
+bitfield CHS {
+	h : 8;
+	s : 6;
+	c : 10;
+} [[right_to_left, format("chs_formatter")]];
+
+fn chs_formatter(CHS chs) {
+	return std::format("({:X}, {:X}, {:X}) | 0x{:X}", chs.c, chs.h, chs.s, (chs.c * 16 + chs.h) * 63 + (chs.s - 1));
+};
+
+enum PartitionStatus : u8 {
+	None = 0x00,
+	Active = 0x80
+};
+
+enum PartitionType : u8 {
+	EmptyPartitionEntry = 0x00,
+	FAT32_CHS = 0x0B,
+	FAT32_LBA = 0x0C
+};
+
+namespace fat32 {
+
+	u64 bytesPerCluster;
+
+	struct FSInfo {
+		u32 leadSignature;
+		padding[480];
+		u32 structSignature;
+		u32 freeClusterCount;
+		u32 nextFreeCluster;
+		padding[12];
+		u32 trailSignature;
+	};
+	
+	bitfield SequenceNumber {
+		padding : 1;
+		lastLogical : 1;
+		padding : 1;
+		number : 5;
+	} [[left_to_right]];
+	
+	enum EntryStatus : u8 {
+		Regular = 0x00,
+		DotEntry = 0x2E,
+		DeletedEntry = 0xE5
+	};
+	
+	union EntryStatusOrSequenceNumber {
+		EntryStatus entryStatus;
+		SequenceNumber sequenceNumber;
+	};
+	
+	bitfield Attributes {
+		readOnly : 1;
+		hidden : 1;
+		systemFile : 1;
+		volumeLabel : 1;
+		subdirectory : 1;
+		archive : 1;
+		padding : 2;
+	} [[right_to_left]];
+	
+	struct DirEntry {
+		char fileName[8];
+		char extension[3];
+		Attributes attributes;
+		u8 reserved[10];
+		u16 time, date;
+		u16 startingCluster;
+		u32 fileSize;
+		
+		u8 data[fileSize] @ startingCluster * bytesPerCluster;
+	};
+	
+	struct VFATDirEntry {
+		EntryStatusOrSequenceNumber entryStatusOrSequenceNumber;
+		char16 name1[5];
+		Attributes attributes;
+		u8 type;
+		u8 nameChecksum;
+		char16 name2[6];
+		u16 startingCluster;
+		char16 name3[2];
+		
+		if (entryStatusOrSequenceNumber.sequenceNumber.number > 1)
+			VFATDirEntry nextLogicalEntry;
+		else
+			DirEntry physicalEntry;
+	};
+
+	struct Partition {
+		u8 jmpCode[3];
+		char oemName[8];
+		u16 bytesPerSector;
+		u8 sectorsPerCluster;
+		u16 reservedAreaSize;
+		u8 numFats;
+		u16 rootEntryCount;
+		u16 numSectors;
+		u8 mediaType;
+		u16 fatSize;
+		u16 sectorsPerTrack;
+		u16 numHeads;
+		u32 numHiddenSectors;
+		u32 numFsSectors;
+		u32 numFatSectors;
+		u16 extFlags;
+		u16 fsVersion;
+		u32 rootCluster;
+		u16 fsInfoSector;
+		u16 backupBootSector;
+		padding[12];
+		u8 driveNumber;
+		padding[1];
+		u8 bootSignature;
+		u32 volumeID;
+		char volumeLabel[11];
+		char fsType[8];
+		u8 bootstrapCode[420];
+		u16 signature;
+		
+		bytesPerCluster = (sectorsPerCluster * 1024) * bytesPerSector;
+		
+		FSInfo fsInfo @ addressof(this) + fsInfoSector * bytesPerSector;
+		VFATDirEntry rootDirEntry @ addressof(this) + rootCluster * bytesPerCluster;
+	};
+
+}
+
+struct PartitionEntry {
+	PartitionStatus status;	
+	CHS chsFirstSectorAddress;
+	PartitionType type;
+	CHS chsLastSectorAddress;
+	u32 lbaFirstSectorAddress;
+	u32 numSectors;
+	
+	if (type == PartitionType::EmptyPartitionEntry)
+		continue;
+	else if (type == PartitionType::FAT32_CHS || type == PartitionType::FAT32_LBA)
+		fat32::Partition partition @ lbaFirstSectorAddress * 512;
+};
+
+struct MasterBootRecord {
+	u8 bootstrapCodeArea1[218];
+	padding[2];
+	u8 originalPhysicalDrive;
+	DiskTimeStamp diskTimeStamp;
+	u8 bootstrapCodeArea2[216];
+	u32 diskSignature;
+	DiskProtection diskProtection;
+	PartitionEntry partitionEntries[4];
+	u16 bootSignature;
+};
+
+MasterBootRecord mbr @ 0x00;