Re: ENH: SysRq Screen-capture?

Colin Hirsch (hirsch@mystic.informatik.rwth-aachen.de)
Thu, 18 Nov 1999 08:48:23 +0100


Hi There!

> >> Is it possible to put a screen-capture command in the SysRq
> >> stuff? when the kernel panics, it'd be nice to capture the
> >> screen it died on without having to spend ten minutes with
> >> pencil+paper...
>
> > Once it has paniced its a bit late and capture to disk might not
> > be safe
>
> > There are 3) answers
>
> > 1. Serial console
>
> > 2. Use a digital camera (yes I've even had people mail me jpgs
> > of a crash)
>
> > 3. if you need to use pen/paper then 99% of the time the only
> > values you need are the EIP and the call trace.
>
> Can I add a fourth for those able to use it that can't use any of the
> above options...
>
> 4. Use a camcorder to video the dump, then feed that into
> your TV card and turn it into an mpg file.

Coming from Amiga I'd suggest:

5. Once you panic, write the output (+ some magic and/or
checksum) into some fixed memory region and let the
kernel recover it upon next bootup.

Of course this requires some memory that is _not_ cleared at boot
time -- I don't know whether that is available on all architectures.
But it would be convenient to have something like /proc/sys/last_panic.

Regards, Colin

-- 
Dipl.-Inform. Colin Hirsch    hirsch@informatik.rwth-aachen.de
Research Group on Mathematical Foundations of Computer Science
University of Technology Aachen                        Germany
                                                            --

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