diff --git a/metropolis/pkg/fat32/structs.go b/metropolis/pkg/fat32/structs.go
new file mode 100644
index 0000000..396361d
--- /dev/null
+++ b/metropolis/pkg/fat32/structs.go
@@ -0,0 +1,133 @@
+package fat32
+
+const (
+	// FAT32 entries are only 28 bits
+	fatMask = 0x0fffffff
+	// Free entries are 0
+	fatFree = 0x0
+	// Entry at the end of a cluster chain
+	fatEOF = 0x0ffffff8
+)
+
+// FAT32 Boot Sector and BIOS Parameter Block. This structure is 512 bytes long,
+// even if the logical block size is longer. The rest should be filled up with
+// zeroes.
+type bootSector struct {
+	// Jump instruction to boot code.
+	JmpInstruction [3]byte
+	// Creator name. "MSWIN4.1" recommended for compatibility.
+	OEMName [8]byte
+	// Count of bytes per block (i.e. logical block size)
+	// Must be one of 512, 1024, 2048 or 4096
+	BlockSize uint16
+	// Number of blocks per allocation unit (cluster).
+	// Must be a power of 2 that is greater than 0.
+	BlocksPerCluster uint8
+	// Number of reserved blocks in the reserved region of the volume starting
+	// at the first block of the volume. This field must not be 0.
+	ReservedBlocks uint16
+	// The count of FAT data structures on the volume. This field should always
+	// contain the value of 2 for any FAT volume of any type.
+	NumFATs uint8
+	_       [4]byte
+	// Legacy value for media determination, must be 0xf8.
+	MediaCode uint8
+	_         [2]byte
+	// Number of sectors per track for 0x13 interrupts.
+	SectorsPerTrack uint16
+	// Number of heads for 0x13 interrupts.
+	NumHeads uint16
+	// Count of hidden blocks preceding the partition that contains this FAT
+	// volume.
+	HiddenBlocks uint32
+	// Total count of blocks on the volume.
+	TotalBlocks uint32
+	// Count of blocks per FAT.
+	BlocksPerFAT uint32
+	// Flags for FAT32
+	Flags uint16
+	_     [2]byte
+	// Cluster number of the first cluster of the root directory. Usually 2.
+	RootClusterNumber uint32
+	// Block number of the FSINFO structure in the reserved area.
+	FSInfoBlock uint16
+	// Block number of the copy of the boot record in the reserved area.
+	BackupStartBlock uint16
+	_                [12]byte
+	// Drive number for 0x13 interrupts.
+	DriveNumber   uint8
+	_             [1]byte
+	BootSignature uint8
+	// ID of this filesystem
+	ID uint32
+	// Human-readable label of this filesystem, padded with spaces (0x20)
+	Label [11]byte
+	// Always set to ASCII "FAT32    "
+	Type [8]byte
+	_    [420]byte
+	// Always 0x55, 0xAA
+	Signature [2]byte
+}
+
+// Special block (usually at block 1) containing additional metadata,
+// specifically the number of free clusters and the next free cluster.
+// Always 512 bytes, rest of the block should be padded with zeroes.
+type fsinfo struct {
+	// Validates that this is an FSINFO block. Always 0x52, 0x52, 0x61, 0x41
+	LeadSignature [4]byte
+	_             [480]byte
+	// Another signature. Always 0x72, 0x72, 0x41, 0x61
+	StructSignature [4]byte
+	// Last known number of free clusters on the volume.
+	FreeCount uint32
+	// Next free cluster hint. All 1's is interpreted as undefined.
+	NextFreeCluster uint32
+	_               [14]byte
+	// One more signature. Always 0x55, 0xAA.
+	TrailingSignature [2]byte
+}
+
+// Directory entry
+type dirEntry struct {
+	// DOS 8.3 file name.
+	DOSName [11]byte
+	// Attribtes of the file or directory, 0x0f reserved to mark entry as a
+	// LFN entry (see lfnEntry below)
+	Attributes        uint8
+	_                 byte
+	CreationTenMilli  uint8 // Actually 10ms units, 0-199 range
+	CreationTime      uint16
+	CreationDate      uint16
+	_                 [2]byte
+	FirstClusterHigh  uint16
+	LastWrittenToTime uint16
+	LastWrittenToDate uint16
+	FirstClusterLow   uint16
+	FileSize          uint32
+}
+
+const (
+	// lastSequenceNumberFlag is logically-ORed with the sequence number of the
+	// last Long File Name entry to mark it as such.
+	lastSequenceNumberFlag = 0x40
+	// codepointsPerEntry is the number of UTF-16 codepoints that fit into a
+	// single Long File Name entry.
+	codepointsPerEntry = 5 + 6 + 2
+)
+
+// VFAT long file name prepended entry
+type lfnEntry struct {
+	SequenceNumber uint8
+	// First 5 UTF-16 code units
+	NamePart1 [5]uint16
+	// Attributes (must be 0x0f)
+	Attributes uint8
+	_          byte
+	// Checksum of the 8.3 name.
+	Checksum uint8
+	// Next 6 UTF-16 code units
+	NamePart2 [6]uint16
+	_         [2]byte
+	// Next 2 UTF-16 code units
+	NamePart3 [2]uint16
+}