writing ktrace output to serial port

Daniel O'Connor doconnor at gsoft.com.au
Mon Jun 21 18:01:59 PDT 2004


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sun, 20 Jun 2004 23:29, Eugene Grosbein wrote:
> So I want to see what is happening just before my mplayer crashes the
> kernel. The problem is that ktracing mplayer does not help as filesystem
> can't keep ktrace.out being written just before crash. I tried 'sync'
> mount,
> it does not help too.
>
> I decided to divert ktrace.out to /dev/cuaa0 so another FreeBSD will keep
> it. However, ktrace() in src/sys/kern/kern_trace.c does not permit writing
> to non-regular file. Why?

The actual syscall passes a filename, not a file descriptor so you'd have to 
change that (or make a new syscall) if you wanted to change it at all :(

It would be nice to be able to ktrace() to an fd (eg socket or pipe) though :)

See ktrace() in /usr/src/sys/kern/kern_ktrace.c:494

As for your problem..
Can you NFS mount? If you have no ethernet you could NFS mount over 
PPP/SLIP :)
(or PLIP if you have a parallel port)

- -- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)

iD8DBQFA14T/5ZPcIHs/zowRAhaIAJ9oHNNtZ+XHgZpjKIt+cBSV1pyvLACgrG5q
Qxd19+DAEB6xAcph0rSZ5KI=
=Wl8n
-----END PGP SIGNATURE-----


More information about the freebsd-hackers mailing list