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

[Dan Cross]

In article <63a25e5a-2001-451b-b8a7-d6d9e74b02f9n at googlegroups.com>,
John Reagan  <xyzzy1959 at gmail.com> wrote:
>Other than an impact on the boot loader due to the change in startup mode, it has essentially no impact on OpenVMS

Interesting.  I take it OpenVMS itself is entered in 64-bit mode
then?  What about AP startup?  The new SIPI type must surely be
accommodated, or does the loader also start the APs and park
them until the actual OS gets around to using them?

>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.

The same was true of 32-bit x86 as well.  The ring architecture
on x86 was never particularly useful.  I've heard rumors that
OS/2 2.x used it, but beyond that, I don't think it's ever seen
much use.  *shrug*

	- Dan C.