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Re: 'machine check while in PAL mode'?

In debian-alpha Doug Larrick wrote:
>Peter Maydell wrote:
>>halt code = 7
>>machine check while in PAL mode
>>PC = 18400

>As to what "Machine check while in PAL mode" means:
>PAL is Priveleged Architecture Library, and implements various
>low-level functionality, like fault vectors, interrupts, etc.  PAL is
>a chip mode that is supposed to run atomically (i.e.
>non-interruptable).  If an event that triggers PAL mode occurs when
>already executing in PAL mode, you get this machine check.  My sources
>tell me (I work at Compaq in the Alpha group) that there's not much
>left at this point to try to debug what happened.  My machine is a
>Pyxis Rev B board, and has known bugs (in the chipset) relating to
>DMA.  I'd be interested to hear the source of your LX; I've been led
>to believe that revenue-quality boards should not have this problem.

Bought from GND (www.gnd.co.uk) -- I don't have the motherboard manual
to hand but I'll try to remember to look up the model information.

>When I had this problem, I turned off various kernel options (IDE DMA
>especially) and that seemed to restrict the problem to soundcard
>access.  At that point I gave up and went back to AlphaBIOS and MILO,
>and have been running happily ever since.  Evidently the MILO PALcode
>is different enough to not trigger the problem.

I switched from AlphaBIOS to MILO because I want to use a serial
console and to the best of my knowledge AlphaBIOS doesn't support that.
(plus SRM's user interface is much nicer than AlphaBIOS's).

Do I have some other alternative? Perhaps booting from SRM and immediately
replacing the SRM PALcode with something else, preferably something
for which sources are available? Alternatively can MILO be flashed
in as a replacement for SRM altogether on these machines?

Peter Maydell
(knew there was a reason why they called it "alpha" :->)

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