Re: [Qemu-devel] Query on Qemu 1.7.0 GDB server version

[Peter Maydell]

On 2 January 2014 12:13, shabarish s <address@hidden> wrote:
> Which version of gdbserver is implemented in the QEMU 1.7.0  ?

It's a custom implementation of the gdbstub protocol. There is
no "version number" specified by the gdbstub protocol. The
protocol design is that it is always backwards compatible, so older
stubs will return a failure response for new commands they don't
implement, and new stubs continue to support all the old commands.
The debugger is expected to be either able to fall back to working
in a way that works with old stubs, or to stop with a helpful error
message (which is what it sounds like DS-5 has done here):

> ERROR(CMD441-TAD8-NAL60):
> ! Continuing failed
> ! Unable to run device gdbserver
> ! Remote gdbserver did not recognize message

If you want to debug this further to see what DS-5 is actually
trying to do, you need to find a way to dump the raw gdbstub
packets it is sending and receiving. Then you can determine
whether the problem is a bug in DS-5 (not implementing a
good fallback for older debug stubs) or if it would be easier
to implement some new feature in QEMU's debug stub.

thanks
-- PMM