[Info-vax] VMS port to x86

[Sprag]

On Mar 21, 3:32 pm, koeh... at eisner.nospam.encompasserve.org (Bob
Koehler) wrote:
> In article <jkcjcn$p3... at Iltempo.Update.UU.SE>, Johnny Billquist <b... at softjar.se> writes:
>
> > No, they don't.
>
>    Intel, not to mention every other reference I've seen, says they do:
>
> http://www.intel.com/Assets/en_US/PDF/manual/253668.pdf?wapkw=cpu+arc...
>
>    Intel. 64 and IA-32 Architectures
>    Software Developer.s Manual
>    Volume 3A:
>    System Programming Guide, Part 1
>
>    "The processor.s segment-protection mechanism recognizes 4 privilege
>     levels, numbered from 0 to 3."

Yep, for segemented 32 bit mode x86 has 4 levels.  They don't map
directly to the vax levels, but there are 4 of them.  In any case, in
x86-64 there are two levels because it doesn't use segmentation --
just page-level protection.