Reminder that Intel messed up paged memory and effectively made RING1 and RING2 useless.
@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.
@gudenau Doesn’t OS/2 use them?