Re: 2.0.30 reboots with cyrix.pl2.patch

Mike Jagdis (mike@roan.co.uk)
Tue, 22 Apr 1997 13:00:55 +0100 (GMT/BST)


On Tue, 22 Apr 1997, Joseph W. Breu wrote:

> processor : 0
> cpu : 586
> model : 6x86 2x Core/Bus Clock
> vendor_id : CyrixInstead
> stepping : 2 rev 2
> [...]
> After the Uncompressing the kernel... it reboots.
> [...]
> I am not sure if the VSPM is causing this because my chip is a
> step that doesn't have the L1 broken and has the VSPM (I think?)..

If you use VSPM on a system with a non-power of two memory size
the current patch gets the kernel page tables wrong and crashes.

It is also extremely likely that the step 2 chips have completely
different sets of bugs in the VSPM handling (the step 1 revisions
are all different...). Cyrix appear not to document such changes
and are unable to answer technical questions about their chips.
Last I heard my questions were going to be passed down to the
engineers but that was *months* ago. I wouldn't recommend trying
VSPM on anything other than step 1 rev 4-7 unless you are willing
to invest the time to figure out what Cyrix can't/won't tell you :-).

N.B. I believe the M2 will have Pentium 4MB page capabilities
(which, being a compatibility issue, probably means they'll want
it to *work*). What that means for the future of VSPM I don't know.

Mike

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