IOS

IOSU is the operating system running on the ARM in Wii U mode. It is the Wii U equivalent of IOS on the Wii, and similar in some regards, but it is a complete rewrite with many changes. IOSU implements the Wii U's security policy, which includes titles and hardware access. One of its primary responsibilities is enforcing code signing, verifying that all titles launched on the PowerPC are authenticated by Nintendo. Another one of its jobs is managing access to most hardware, such as storage, network, USB, and the Gamepad. The PowerPC can talk to IOSU through an IPC interface, based on the standard Unix filesystem, and make security and hardware requests.