cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386 swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h

[Hidetoshi Shimokawa]

At Tue, 20 Jan 2004 13:48:33 -0600,
Larry Rosenman wrote:
> 
> [1  <text/plain; us-ascii (quoted-printable)>]
> 
> 
> --On Tuesday, January 20, 2004 14:45:05 -0500 Kenneth Culver 
> <culverk at sweetdreamsracing.biz> wrote:
> 
> 
> >> Except when crashdumps don't work or are 1 GB+.  There are a few things
> >> we need:
> >>
> >> * Fix crash dumps.  I can't get a dump on my laptop, ATA.
> >>
> >> * Sparse crash dumps.  We don't need non-anonymous pages, for instance.
> >>
> >> * Fix GDB backtrace output (patch posted by gallatin@ and obrien@ may be
> >> working on integrating it.)
> >>
> >> * Fix backtrace() so the output goes to the console log.  Right now, we
> >> get output that needs to be hand-transcribed or use a serial console.
> >
> > This is also very useful for when FreeBSD crashes when X is running. If X
> > is running, the only option is a serial console, as you can't see the
> > crash to transcribe it otherwise, and most people don't have the spare
> > computer to use as a serial console.

If you enable dcons(4), all (low level) console output are logged into
a buffer in the kernel. You can recover them using dconschat(8) from
the crash dump. (You don't need a FireWire port)

> Or worse, as in my Laptop, NO SERIAL PORT AT ALL :-)

Many laptops has a FireWire port which can be used as a replacement
of a serial console for the most cases. See gdb(4) for detail.
(For i386, you can even take crash dump over FireWire.)

JFYI,

/\ Hidetoshi Shimokawa
\/  simokawa at sat.t.u-tokyo.ac.jp
PGP public key: http://www.sat.t.u-tokyo.ac.jp/~simokawa/pgp.html