[CentOS] How do I debug the kernel?

Tue Mar 6 18:01:48 UTC 2007
Mark Hull-Richter <mhull-richter at datallegro.com>

Probably an odd question, but, as I have said many times before, I'm
more than a little bit rusty on this stuff.  I know I can use gdb to
debug the running kernel, but I'm not sure how to invoke it properly for

Please advise.