Using WiiU File Formats

SigPatch required for NUS format games (*.app etc)

A sigpatch is a modification to the wiiU NAND memory that ‘patches’ the signature checks that are performed for running and installing custom wiiU channels.

This technically allows Virtual Console and other eShop games to be taken from one wiiU and installed on another sigpatched wiiU.

WiiU Game File Formats

WiiU Raw Disc Image (*.WUD)

This is a full dump of a WiiU Disk completely uncompressed, just like it would be on the disc itself.

WIIU Compressed Disc Image (*.WUX)

The same as the raw WUD file but it has been compressed so it has a smaller file size.

WiiU NUS formats (from eShop or extracted discs)

The wiiU Nintendo Update Server format is basically a folder of different files such as .app, .h3 etc. These are all encrypted files. If you buy a game from the Nintendo eShop it is downloaded in this format. You can also convert a disc game to this format using a tool such as Disc Extractor.

*.app files

Numbered starting from 0 (00000000.app) to however big the channel/game is.

App files contain the actual game data, encrypted and split into sections. To decrypt the content you need the title.tmd which stores the meta data for each .app and the title key for decryption (found in the ticket). With this data you can use a AES decrypter pass in the title key and you should be able to extract all the .app files ¹.

*.h3 files

H3 files are file Hashe to verify the downloaded .app file is correct (Each hash is a 20-byte SHA1) ²

title.cert (Certificate chain)

Contains the certificates for the ticket and TMD signers, as well as the certificate authority ³.

This is similar to the Wii Certificate Chain which is outlined here: Certificate chain - WiiBrew

title.tik (Ticket)

Contains the title ID, console ID (for downloaded titles), and encrypted title key³.

The file format is similar to the Wii Ticket format which is documented here: Ticket - WiiBrew.

You can use the homebrew tool tik2sd to get your tickets downloaded to your sd card.

title.tmd (Title Metadata)

The Title Metadata file (.tmd) contains the required IOS version (WiiUOS) and SHA-1 hashes of all of the title’s contents³.

The .tmd file contains all Sha1 of the content, but it’s a SHA1 hash of decrypted files, not encrypted .app files. So it requires decryption and file extraction to check integrity.

---

Decrypted WiiU NUS file formats

When the nus .app files have been decrypted and extracted you will get all the game files you need for modding/reversing. The main files we are interested in are RPX and RPL.

RPL (Revolution Plus Library?) File

RPL is a Code Library. Stuff like coreinit.rpl are libraries ⁴.

RPX (Revolution Plus eXecutable?) File

RPX is a Wii U Executable. You need Code, Content, and Meta folders to use these ⁴.

RPX to ELF conversion

Relys/rpl2elf: Small utility to convert Wii U RPL/RPX files to standard ELF format

Open RPL/RPX in IDA PRO

Youtube video: (188) [Wii U] Analyzing Wii U Executables with IDA Pro Setup Tutorial - YouTube

Source code to the IDA pro loader: ida_gel/src/wiiu at master · aerosoul94/ida_gel

---

WiiU Asset File Formats

SZS Compressed File Format

A SZS file is actually just a YAZ0 compressed asset that could be any other format, it is just a common extension used to show its compressed with YAZ0. For more information: SZS (File Extension) - Custom Mario Kart

WiiU Localised Text Format (.msbt)

This is used in many different wiiU games and is presumably part of the wiiU SDK.

Thanks to the excellent folk over at the custom Mario Kart wik we have documentation about this format: MSBT (File Format) - MK8

.BCRES File Format (.CGFX, .BCMDL)

The BCRES format was used in many 3DS games but only used in one WiiU game that we know of which is Battle Tank Hero.

The game was released on 3DS first and then later ported to wiiU, but it is surprised this is the only game that uses this format.

For more information visit: CGFX - The VG Resource Wiki

GTX Texture format

aboood40091/GTX-Extractor: Wii U ‘GTX’ Texture Extractor

WEM Audio Format (WWISE)

The format was developed by WWise for their audio creation software and used in a number of WiiU titles including:

• Batman Arkham Origins Blackgate
• Trine 2
• Chariot
• LOST REAVERS

Binary caFe Layout IMage (.bflim)

The BFLIM file format (Binary caFe Layout IMage) is used to store layout images. ⁵ The following tools can handle BFLIM files:

• BFLIM Tool, by AboodXD
• BFLIMtoGTX, by RandomTalkingBush
• Wexos’s Toolbox, by Wexos

---

Other WiiU File Formats

Game Virtual Manual (.bfma)

The Game Manual format is a SARC archive that can be extracted using UWizard. It contains both xml and a number of .arc files ⁶.

References