contrib/FAQ/OTHER-FAQS/FreeBSD.kdebug.FAQ

                   Kernel debugging FAQ
                       FreeBSD

Last modified: $Id$

Here are some instructions for getting kernel debugging working on
a crash dump, it assumes that you have enough swap space for a crash
dump.

*** Start ***

Config you're kernel using config -g

Remove ${STRIP} -x $@; from the Makefile for the kernel so it doesn't
get stripped.

When the kernel's been built make a copy of it, say 386BSD.debug, and
then run strip -x on the original. Install the original as normal.

Now, after a crash dump, go to /sys/compile/WHATEVER and run kgdb. From kgdb
do:

symbol-file 386BSD.debug
exec-file /var/crash/system.0
core-file /var/crash/ram.0

and viola, you can debug the crash dump using the kernel sources just like
you can for any other program.


  Paul Richards, FreeBSD core team member.