File Header

Size	Type	Name	Notes
4 Bytes	uint32	Signature	0x9e2a83c1
2 Bytes	int16	Version	Bns is 573
2 Bytes	int16	LicenseeVersion	BnS is 1
4 Bytes	int32	HeaderSize	Includes all of the Header, Name, Export, Import and Depends tables
variable	UpkString	GroupName	BnS is "None"
4 Bytes	uint32	PackageFlags
4 Bytes	int32	NameCount	Count of entries in the Name Table
4 Bytes	int32	NameOffset	Pointer to the start of the Name Table
4 Bytes	int32	ExportCount	Count of entries in the Export Table
4 Bytes	int32	ExportOffset	Pointer to the start of the Export Table
4 Bytes	int32	ImportCount	Count of entries in the Import Table
4 Bytes	int32	ImportOffset	Pointer to the start of the Import Table
4 Bytes	int32	DependsOffset	Pointer to the start of the Depends Data/Table
16 Bytes	GUID	GUID	Package Global Unique Identifier
variable	UpkArray	Generation Table	Inline with the header
4 Bytes	int32	EngineVersion
4 Bytes	int32	CookerVersion
4 Bytes	uint32	CompressionFlags
variable	UpkArray	CompressedChunk Table	Inline with the header
4 Bytes	uint32	Unknown1	Unknown random value
4 Bytes	uint32	Unknown2	Always 0x00000000