Re: [Qemu-devel] Documentation/tools on debuging dyngen code?

["Mulyadi Santosa" <mulyadi.santosa@gmail.com>]

On 10/2/08, Bruce Beare (bbeare) <bbeare@cisco.com> wrote:
> I'm working on a 2.6.24 Linux port built for ARCH=powerpc and configured
> for the PReP machine. I have the port booting using an unmodified 0.9.1
> version (actually, head from the SVN repo) of qemu-system-ppc but
> sometimes find that QEMU "hangs". Analysis of the hang reveals:
>
>   o C-A C-X does not respond
>   o QEMU is sucking up 100% cpu time of one processor
>   o GDB to the kernel debug port (qemu option -s -p 1234) is non
> responsive
>   o ltrace, strace show no system or library calls in progress
>   o GDB on QEMU shows that it is executing apparently valid code in the
> 0x4xxxxxxx
>     range.
>
> My conclusion is that QEMU is looping while executing the dynamically
> generated code. I'd like to debug this further... and am looking for
> some pointers on how to do so. Is there a built-in debugger? Is there a
> particular probe point that I should set a GDB breakpoint on? What is
> the general procedure for doing this level of debug?

I suggest to observe the generated code first. Explore the -d option
of qemu. For complete list of what you can log, use "qemu -d ?".

regards,

Mulyadi