Re: port-xen/53267 (XEN amd64 DomU (Dom0??) NetBSD current USERMODE() fails)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sat, 12 May 2018 00:36:25 -0700
    From:        John Nemeth <jnemeth%cue.bc.ca@localhost>
    Message-ID:  <201805120736.w4C7aP9t028295%server.cornerstoneservice.ca@localhost>

Thanks for taking the trouble to explain all of that.

In particular:

  |      AMD noted that rings 1 and 2 weren't used much and dumped them
  | as unused legacy stuff. 

which explains a lot - I had wondered why they were not used.

kre

ps: I still think the 8080 was the worst of the competing 8 bit processors
of the time, and while I applaud Intel's capacity to extend it while more
or less keeping complete compat with ancient code, I really wish that IBM
had selected one of the other choices...