Data containers

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The Nintendo Wii code and data is stored using several data structures present in different types of media.

This page is an overview of said containers and structures.

(Feel free to fix any missed information or misinformation in this page).

Logical Containers

Disc Partitions

The discs used on the Nintendo Wii are structured in one or more self-contained subdivisions called "partitions". Partitions contain encrypted data blocks (0x8000 bytes per block, or 32k) protected by encrypted SHA-1 hashes signed by a RSA signature. The encryption and hashing is carried at the block layer, independent of the file system used (FST).

Each partition is encrypted using a 'title key' that can be derived from a common key and the ticket in the partition.

The structure of a partition is described in the Wiidisc page.

Title MetaData (TMD)

The TMDs are structures used in several places (disc partitions, etc.) to describe a set of signed content.

The structure of a TMD is described in the Tmd file structure page.


WAD Files

These files are encrypted file containers. They are used for example within gamesaves and firmware updates.

The process to decrypt WAD files is similar to the one used for the discs.

The format of a WAD file is described in the WAD Files page.


These files are used by games to preserve the state of game play.

The format, which is a special header followed by a WAD file, is described in the Savegame Files page.

Channels saved to SD (content.bin)

These files are generated when a channel (Wii or VC) is saved to an SD card.

This format is described in Content.bin file structure.

U8 archives

This is an archive format (no compression) which is used in several places.

The format is described on the U8 archive page.

DVD game banner (opening.bnr)

This is the file that describes the banner shown in the channel selector when a game disc is inserted.

The format is described on the opening.bnr page.

RARC Files

These files are compressed file containers. The compression seems to be the same as in the GameCube RARC format.

The format of a RARC file is described in Yet Another GameCube Documentation by Groepaz/Hitmen.

Yaz0 Files

These files are compressed files. The compression seems to be the same as the one used in the GameCube Yaz0 format.

The format of a Yaz0 file is described in Yet Another GameCube Documentation by Groepaz/Hitmen.



Seems to be an archive format.

These informations are taken by investigating some .pac-files of the fighters of ssbb (the currently only known game that uses those archives).

  • first 3 bytes -> ARC
  • starting at 0x10 -> Filename without extension
  • starting at 0x60 -> Beginning of the archived file, in the case of those .pac-files of the fighters they all seem to be .brres-files
An Example of a .pac-archive

As you can see in that image of a file (FitLink00.pac) of the SSBB-Disc, the file which is stored in the .pac is called FitLink00.bres and residents in the /-folder


Seems to be an compressed version of the the PAC-Archive

CCF files:

This is an archive format that supports optional ZLib compression. The format is described on the CCF archive page.

BMG files:

Stores strings used in games for localization. Starts with 4 byte ascii text MESG, contains INF and DAT sections. DAT section contains the unicode strings. Can be found in a Wii Fit disc.

Ticket/TIK files:

Tickets are found in many encrypted files used by the Wii (e.g. WAD Files or Wiidiscs). They contain the encrypted AES key and the Title ID of the data followed by a certificate chain.

The format of ticket files is described in the Ticket page.

BRSTM files:

BRSTM files seem to contain sound data. They're used in Mario Kart Wii.

The format of these files is described in the BRSTM file page.