|License||GNU GPL v2|
PatchMii is a tool designed to automatically patch IOS as it gets downloaded from NUS. It contains a framework used to work with IOS in general, but it also includes a piece of code that downloads the latest version of IOS37, makes 2 patches, and installs the patched IOS in the IOS254 slot (IOS5 on older versions).
The signature patch nulls out a single instruction that jumps to the hash checking code.
The drivechip patch changes 4 bytes related to DVDLowUnencryptedRead to FFFFFFFF, probably to make this ioctl always fail, so error 001 cannot be detected.