Re: [Xen-devel] debugging xen ....

Himanshu Raj
Wed, 24 Aug 2005 11:55:21 -0000

Hi Tim,

Thanks for the reply. I will try this out asap. However, just looking at it,
this looks like a solution to debug guests running under xen. I am more
interested
in debugging xen itself. Can you shed any light on that?

Thanks,
Himanshu

On Tue, Aug 23, 2005 at 09:30:54PM -1000, Tim Newsham
wrote:
> >After looking around for a howto and asking ppl on IRC, I had to come
back
> >to the forum for this - how to debug xen?
> >
> >Basically, I would love to be able to step through the code using gdb
> >connected
> >serially to another machine.
> >
> >Is there some functionality like that in Xen. I also found some emails
> >referencing
> >a XenDebugger-HowTo, however I couldn''t find that file
anywhere.
>
> Run the build script in xen-unstable.hg/tools/debugger/gdb.
> Install the gdbserver and gdb (I put them in /usr/local/bin
>   as gdbserver-xen and xengdb).
> Build your kernel with debug.  I use the flags
>   "verbose=y domu_debug=y debug=y".  although I dont know if
these
>   are all required.
> Start up your domain (I use vm-tools and do all the steps except
>   the vm-pause step).
> Run gdbserver.  I run "gdbserver-xen 127.0.0.1:9999 --attach
$dom"
> Run gdb.  I run "xengdb -x remgdb" where remgdb has the command
>   "target remote 127.0.0.1:9999" in it.
>
> Tada, you''re in a debugger.
>
> I use the following script to automate this tedious process:
>
> --- deb.sh ---
> #!/bin/sh
>
> run()
> {
>         echo "$*"
>         $* || (echo ''failed''; exit 1)
> }
>
> # vm-create isnt giving us the right answer...
> dom=`vm-create`
> echo dom is $dom
>
> run vm-memory -m $dom 64m
> run vm-memory -i $dom 64m
> run vm-build.linux $dom /root/kernel
>
> echo done $dom
> gdbserver-xen 127.0.0.1:9999 --attach $dom &
> sleep 1
> xengdb -x /root/remgdb
>
> run vm-pause -u $dom
> --- end deb.sh ---
>
> >Himanshu Raj
> >PhD Student, GaTech (www.cc.gatech.edu/~rhim)
>
> Hope this helps,
> Tim Newsham
> http://www.lava.net/~newsham/

--
-------------------------------------------------------------------------
Himanshu Raj
PhD Student, GaTech (www.cc.gatech.edu/~rhim)
I prefer to receive attachments in an open, non-proprietary format.
-------------------------------------------------------------------------