The PS4 and Xbox One have a x86 processer which means that it's architecture is the same as pc. Basically it is built like a powerfull computer but uses optimized OS that dedicates it's resources to the game, well the PS4 does a good job at that, Xbox is pree f*ing stupid when they made their game plan. With that said the OS they use isn't Windows like the Type X/X2/X3. It is a OS built upon it's UNIX in the case for PS4 not sure how they made Xbox. It would be an emulator not a loader for those reasons.