There are different definitions of alternative OS. I'm guessing yours is a different build of Android with the original kernel blobs transplanted from the OEM r

There are different definitions of alternative OS. I'm guessing yours is a different build of Android with the original kernel blobs transplanted from the OEM rom. The other one is being able to run mainline linux or a custom OS from scratch. If Linux didn't already exist it would never have been possible to create since all computing platforms are getting more and more locked down.