Re: debugging xen ....

[Himanshu Raj <rhim@cc.gatech.edu>]

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/

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Himanshu Raj
PhD Student, GaTech (www.cc.gatech.edu/~rhim)
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