Wii system software

Wii system software is a set of updatable firmware versions, and a software frontend on the Wii video game console. Updates, which are downloaded via the system's Internet connection (WiiConnect24), allow Nintendo to add additional features and software. When a new update becomes available, Nintendo sends a message to connected systems notifying them of the available update.

Several game discs, both first-party and third-party games, have included system software updates so that players who are not connected to the Internet can still update their system. Additionally this can "force" an upgrade by requiring the player to perform the update, without which the new game cannot be played. Some online games (such as Super Smash Bros. Brawl and Mario Kart Wii) have come with specific extra updates, such as being able to receive posts from game-specific addresses, so, regardless of the version of the installed software, it will install an update.

IOS
The Wii's firmware is in the form of IOSs (thought by the Wii homebrew developers to stand for 'Input Output Systems' or 'Internal Operating Systems' ), which run on a separate ARM architecture processor to other Wii software (nicknamed Starlet by the Wii homebrew community, as it is physically located inside the graphics chip, the Hollywood, so it is a small part of Hollywood. The patent for the Wii U indicates a similar device which is simply named "Input/Output Processor" ). These control input and output between the code running on the main processor (the PowerPC "Broadway" processor) and the Wii's hardware features that did not exist on the GameCube, which can only be accessed via the ARM.

When Nintendo releases a new IOS version, except for unusual circumstances (for example security updates to block homebrew), the new IOS does not replace any IOS already installed. Instead, it gets installed in addition to any current IOS versions. All native Wii software (including games distributed on Nintendo optical discs, the System Menu itself, Virtual Console games, WiiWare, and Wii Channels), with the exception of certain homebrew applications, have the IOS version hardcoded into the software.

When the software is run, the IOS that is hardcoded gets loaded by the Wii, which then loads the software itself. If that IOS does not exist on the Wii, in the case of disc-based software, it gets installed automatically (after the user is prompted). With downloaded software, this should not theoretically happen, as the user cannot access the shop to download software unless the player has all the IOS versions that they require. However, if homebrew is used to forcefully install or run a piece of software when the required IOS does not exist, the user is brought back to the system menu.

Nintendo created this system so that new updates wouldn't unintentionally break compatibility with older games, but it does have the side effect that it uses up space on the Wii's internal NAND Flash memory. IOSes are referred to by their number, which can theoretically be between 0 and 254, although many numbers are skipped, presumably being development versions that were never completed.

Only one IOS version can run at any given time. The only time an IOS isn't running is when the Wii enters GameCube backward compatibility mode, during which the Wii runs a variant of IOS specifically for GameCube games, MIOS.

System Menu
The System Menu provides a graphical interface to the Wii's abilities. All games run directly on the Broadway processor, and either directly interface with the hardware (for the hardware common to the Wii and GameCube), or interface with IOS running on the ARM architecture processor (for Wii-specific hardware). The ARM processor does not have access to the screen, and therefore neither does IOS. This means that while a piece of software is running, everything seen on the screen comes from that software, and not from any operating system or firmware. This includes the home menu (a menu of uniform appearance that appears when the home button is pressed in any piece of official Wii software), and any error messages that might appear. Therefore, the version number reported by the Wii is actually only the version number of the System Menu. This is why some updates do not result in a change of the version number: the System Menu itself is not updated, only (for example) IOSes and channels. As a side effect, this means it is impossible for Nintendo to implement any functions that would affect the games themselves, for example an in-game system menu (similar to the Xbox 360's in-game Dashboard or the PS3's in-game XMB).

Wii System Update releases
This is a list of features included in Wii's System Updates.

Wii Channel releases and updates
This is a list of the updates and releases of Wii Channels.

§ = Released as part of a system update so a separate download is not required.

Discontinued channels (as of 28th June 2013):


 * News Channel
 * Forecast Channel
 * Everybody Votes Channel
 * Mii Contest Channel/Check Mii Out Channel
 * Nintendo Channel