IOS254 is commonly used for various purposes:
- BootMii as an IOS, is installed to this slot.
- PatchMii installs to this slot.
- 3.4 and 3.5 included a copy of IOS9 as IOS254 to overwrite PatchMii, as that was the last place (besides IOS16) the signing bug could be exploited. Each IOS9 update was then copied to this IOS.
- The 4.3 update included a Stub IOS in this slot, in an attempt to overwrite BootMii/IOS, which succeeded for BootMii versions earlier than 1.4. Versions 1.4 and above use version 65281 to prevent this.