From: clc5q AT cobra DOT cs DOT Virginia DOT EDU (Clark L. Coleman)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: CWSDPMR0: system crash on INVD
Date: 28 Mar 2001 22:20:52 GMT
Organization: University of Virginia
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In article <99ta4e$r99$1 AT nets3 DOT rz DOT RWTH-Aachen DOT DE>,
Hans-Bernhard Broeker  <broeker AT physik DOT rwth-aachen DOT de> wrote:
>Clark L. Coleman <clc5q AT cobra DOT cs DOT virginia DOT edu> wrote:
>> I thought that was what CWSDPR0.EXE was all about -- providing access
>> to such instructions. 
>
>Not exactly "providing", but rather "allowing" it, in principle.
>CWSDPR0.exe is a DPMI server that doesn't force the DPMI client
>(i.e. the DJGPP application) into Ring 3. But for that to work,
>CWSDPR0.exe itself needs to run at Ring 0. If the DOS environment
>you're running it in restricts it to Ring 3, there's nothing it can do
>about that.
>
>I.e. I'd suspect your DOS (DrDOS, wasn't it) to be the real culprit,
>here.

If that were the case, and I were running in Ring 3, then how would I
be successfully executing every other Ring 0 instruction that I have
tried besides INVD ? In the portion of my post that you deleted, I
clearly stated that I have been executing instructions such as WBINVD
and WRMSR for more than a year in this environment.

Clark Coleman