DT-LS Filesystem

Overview

Almost all of smash 4's game data is stored in one or more very large "DT" archives. On the 3ds, there is only one of these archives. The WiiU version however contains 2, and a version 2 "LS" file. Version 2 of the LS file allows DT files to be indexed. (e.g DT00, DT01, DT02.) The files within a directory are commonly (but not always) packed into a single file named "PACKED" without any information about the contained files such as size or length.

The PACKED files and any non packed files are stored in the DT archive back to back in chunks, again without information about the files themselves. The info about the data chunks and PACKED files is stored inside the LS file.

LS File

There are two versions of the LS file spec. The first was introduced with the 3ds version, and later the second was introduced in updates and in the wiiu version. The biggest difference between the two versions is the addition of a field to specify what DT file contains the associated data.

Header

Size = 0x08

Offset	Name	Description
0x00	ASCII tag	"of"
0x02	Version	LS file version
0x04	Entry count	Number of LSEntries in the file

LSEntry

Offset	Name	Description
0x00	CRC	CRC32 of the path to this entry's data.
0x04	Chunk offset	Offset to the data chunk for this entry
0x08	Chunk Length	Length of the data chunk for this entry
0x0C	DT index	Only seen in LSEntry v2
0x0E	unk	Only seen in LSEntry v2

Archive Partitions

Since the game has options for multiple languages per region, the game has separate partitions containing the files which are changed per language. In order to view the contents of these partitions, we need the "resource" files which contain the specific information for directories and files (the info that was left out of the DT archive).

For base game dumps, the resource files are placed in the root of the archive. In order to extract it, we need to calculate the CRC32 of the string "resource" (with the first 4 byte's bits inverted) and search for the LS file entry associated with it. Using the LS entry, we can extract the file and begin using it to extract the rest of the files from the partition.

Luckily, there is a default resource file just called "resource" that's defaulted to when files either fail to load, or the file doesn't have a localized variant. The resource files are simply named "resource". If the resource file is for a localized partition, it will have "(xx_xx)" appended to the end where xx_xx is the locale. e.g "(us_en)"

Resource File

The resource files contain file and directory specific information such as flags, data offset, file size, etc. The basic structure of the resource file's is as follows: Header, EntrySection, StringSection.

All data after the header is zlib compressed.

Header

Size = 0x80

Offset	Name	Description
0x00	ASCII Tag	"RF"
0x02	Flags.	0x4 = Compressed, 0x3 = console type: 1 = 3ds, 2 = wiiu
0x04	Content start
0x08	Content size.	0 if compressed.
0x0C	EntrySection offset
0x10	EntrySection Length
0x14	Unix Timestamp
0x18	Compressed Len	Compressed size of the Resource File Data.
0x1C	Decompressed Len	Decompressed size of the Resource File Data.
0x20	StringSection offset
0x24	StringSection Len
0x28	ResourceEntry Count	Number of ResourceEntries in the file.
0x2C - 0x7C	Padding	0x54 bytes of 0xAA

Resource Entry

Offset	Name	Description
0x00	Chunk Offset	Offset relative to the start of the data chunk containing this entry's data.
0x04	String Offset	Offset into the string section for this entry
0x08	Compressed Len	Compressed Length of the data for this entry
0x0C	Decompressed Len	Decompressed Length of the data for this entry
0x10	Unix Timestamp
0x14	Flags	Flags for this entry. See below.

Resource Flags

Bits	Description
0 - 3	Folder Depth
4 - 8	Unknown. Always 0.
9	Is Directory
10	Is File
11	Has localization data
12	Is PACKED
13	debug.
14	External. True if the file should be loaded from outside it's PACK