On 2014-11-04, at 17:07, Tony Thigpen wrote: > The first bit of the address in the PSW indicates that the address is a 31 > bit address. So, there was ambiguity for any address with the first bit set > on. > Was the bit on because it was 31bit code setting the flag, or was it a real > address in 64bit mode? > It was easier to just block out the range as unusable. > Wouldn't that be similarly true for ranges such as 6GiB <= A < 8GiB, 10 GiB <= A < 12 GiB, ...? Are all such ranges blocked out?
-- gil
