@SuperFloppies @gudenau I'm not really sure but I do remember quite a few "Ring 0" errors that were the equivalent of the blue screen of death.

@SuperFloppies I don't know, but there is only one bit in the page tables for permission. RING0 and RING3 only.

@gudenau Ah, I see. Support for more than two rings was removed in Long Mode.

That seems pretty silly. But only one major OS ever used it, and so I guess nobody really needs anything more than user and supervisor.

@SuperFloppies But now that security is actually something people seem to care about now it would be so useful.

@SuperFloppies Pretty sure long mode still has RING1 and RING2, but the memory paging doesn't support it right.