|Type||System Menu IOS|
|Status||Private Corporate IOS|
IOS4 was a very primitive IOS that was used by both the Startup Disc Menu and the System Menu used in the factory process. This IOS and the System Menu come preburnt at the factory, before any other discs are inserted.
U.S. update partitions are set to use this IOS in their TMD. Other regions are not yet known.
|Version||Signing bug?||ES_Identify / /dev/flash?||STM Release Exploit?||Notes|
|v1||Yes||Yes||?||Used by older versions of the Factory System Menu and 0000.|
|v3||Yes||Yes||?||Used in Startup Disc Menu and newer versions of the Factory System Menu.|
|v259||N/A||N/A||N/A||Stub IOS preinstalled on Korean RVL-CPU-20 consoles.|
|v65280||N/A||N/A||N/A||Stub IOS released in 3.3rev03 and 3.5.|