[Info-vax] Intel proposal to simplify x86-64

[Scott Dorsey]

Johnny Billquist  <bqt at softjar.se> wrote:
>On 2023-06-06 19:55, Scott Dorsey wrote:
>> John Dallman <jgd at cix.co.uk> wrote:
>>> In article <63a25e5a-2001-451b-b8a7-d6d9e74b02f9n at googlegroups.com>,
>>> xyzzy1959 at gmail.com (John Reagan) wrote:
>>>
>>>> Other than an impact on the boot loader due to the change in
>>>> startup mode, it has essentially no impact on OpenVMS
>>>>
>>>> OpenVMS does not use ring 1 or 2.  The 64-bit mode PTEs don't
>>>> include support for ring 1 or 2 today, just ring 0 and 3.
>>>
>>> Thanks, glad to hear it.
>> 
>> I'm not necessarily glad to hear it because I like the idea of keeping
>> device drivers in a different ring than user processes or kernel....
>
>Hmm. Am I misremembering something? As far as I can recall, device 
>drivers in VMS (at least on VAX) are running in kernel mode. RMS in EXEC 
>and DCL in SUPER (or was it the other way around?).

Yes.  It's a shame.  When the new i386 rings came out I was thinking 
"Wow, we could do Honeywell-style stuff and it's not a mess like the
286 but... then nobody ever did.

>But the difference are really just what the access rights to different 
>pages are. Kernel is the only one that truly is a bit more special.

Yes.
--scott
-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."