Changes

IOSes are the software that control communications between the PPC and the Wii's hardware, via the ARM processor. To aid in backwards-compatibility, Nintendo decided that each IOS would have its own version number and be stored alongside all the other IOSes on the system. This means when they implement new functions into IOS, they don't have to test every game in existence - just roll out a new IOS. Each game, channel and System Menu chooses which IOS to run - if it is not installed, the Wii usually either crashes or returns to the system menu. This in practice is impossible without homebrew, as the system menu forces you to install updates from disc-based games before you can play them, and you can't access the shop channel without the latest update normally. This has obvious disadvantages that were many times exploited by homebrew - with so many IOSes, if a fatal bug is discovered in all of them, they take a long time to update, test, and deploy - and this has happened time and time again. Since homebrew can also reload into a different IOS version during runtime, a flaw in just one IOS can bring the entire system's security down. This also means that if somehow one IOS is expected but not installed, stuff will go wrong, including some games/channels not working, or bricking - these can only really happen by the cause of homebrew (mostly failpacks - see the next paragraph).

IOSes are the software that control communications between the PPC and the Wii's hardware, via the ARM processor. To aid in backwards-compatibility, Nintendo decided that each IOS would have its own version number and be stored alongside all the other IOSes on the system. This means when they implement new functions into IOS, they don't have to test every game in existence - just roll out a new IOS. Each game, channel and System Menu chooses which IOS to run - if it is not installed, the Wii usually either crashes or returns to the system menu. This in practice is impossible without homebrew, as the system menu forces you to install updates from disc-based games before you can play them, and you can't access the shop channel without the latest update normally. This has obvious disadvantages that were many times exploited by homebrew - with so many IOSes, if a fatal bug is discovered in all of them, they take a long time to update, test, and deploy - and this has happened time and time again. Since homebrew can also reload into a different IOS version during runtime, a flaw in just one IOS can bring the entire system's security down. This also means that if somehow one IOS is expected but not installed, stuff will go wrong, including some games/channels not working, or bricking - these can only really happen by the cause of homebrew (mostly failpacks - see the next paragraph).

Common bugs from the distant past in IOSes that are constantly resurrected by very dangerous means (Wiibrew usually calls them failpacks, because they fail) to aid piracy include the [[Trucha bug]] and the ES_Identify bug - the first allows you to essentially bypass most of the Wii's signature checks (for example, so you can install any channel you want); the second allows you to become the "root user", "system administrator" or whatever you want to call it on the Wii. Mostly nowadays, these are used to aid piracy, but there are quite a few legitimate uses too - and so discussing and using these bugs is generally allowed, as long as you have the means to do it.

Common bugs from the distant past in IOSes that are constantly resurrected by very dangerous means (Wiibrew usually calls them failpacks, because they fail) to aid piracy include the [[Trucha bug]] and the ES_Identify bug - the first allows you to essentially bypass most of the Wii's signature checks (for example, so you can install any channel you want); the second allows you to become the "root user", "system administrator" or whatever you want to call it on the Wii. Nowadays, these are mostly used to aid piracy, but there are quite a few legitimate uses too - and so discussing and using these bugs is generally allowed, as long as you have the means to do it.

Nintendo and BroadOn eventually picked up a particularly nasty habit of "stubbing" IOSes no longer used - reducing them to a non-functional stub of what they used to be. This means that if you downgrade ONLY the System Menu without also downgrading its IOS, there is a strong chance of a brick.

Nintendo and BroadOn eventually picked up a particularly nasty habit of "stubbing" IOSes no longer used - reducing them to a non-functional stub of what they used to be. This means that if you downgrade ONLY the System Menu without also downgrading its IOS, there is a strong chance of a brick.