This is a strange accusation. The repo linked as proof (
https://github.com/derek57/libogc) consists of over 100 commits meticulously converting the libogc codebase to look more like the RTEMS codebase, and claiming that's enough proof that it's the same codebase. I wonder if it'd even build, or if those changes didn't break anything?
Regardless of whether there's any truth to this anonymous accusation, this doesn't seem like the right way to go about it. An article walking through some of the similarities would be much more helpful to prove the point (and probably less work for whoever went through this exercise).
At least provide some links to RTEMS code comparing the libogc code. The OP cites these (https://github.com/devkitPro/libogc/blob/52c525a13fd1762c103... and https://github.com/atgreen/RTEMS/blob/2f200c7e642c214accb7cc...), but that's hardly a smoking gun. The function is trivial, just filling in some struct fields. The logic for choosing the stack size is the same, but it's also trivial and I'd just as likely attribute it to the function interface.
I'm not saying it isn't true, I just find this to not be the most credible accusation I've seen. This feels like some opensource drama thing, and the readme doesn't help, being both lacking information and including lines like:
> How disgusting...
EDIT:
also, they have another serious accusation without ANY proof:
> we discovered that large portions of libogc were stolen directly from the Nintendo SDK or games using the Nintendo SDK (decompiled and cleaned up).