Commands for a minimal GDB stub?

Tristan Gingold
Tue Nov 24 13:51:00 GMT 2015

> On 24 Nov 2015, at 14:38, Clifford Wolf <> wrote:
> Hi,
> I'm trying to write a minimal GDB stub. The documentation states that it is
> sufficient to implement the g, G, m, M, c, and s commands and that $#00
> should be returned for any command not supported by the stub:
> I've now started by implementing a minimal stub that just returns $#00 to
> everything. This is the conversation my stub is having with gdb (not
> showing the '+' acknowledgments, '->' for packets from gdb and '<-' for
> packets from my stub):


> I did compare that to what I record when gdb is talking to gdbserver, and
> the general syntax seems to be the same, meaning I don't think I have
> screwed up implementing the low-level protocol..
> Is the documentation correct and I only need to implement g, G, m, M, c,
> and s? If so: What did I do wrong?

I think the documentation is slightly incorrect.  For an almost minimal
gdb stub, I have also implemented:
?, z, Z, qSupported, qC, qSymbol::, P, k, H

z, Z, H, k, qSupported returned $#00.

You shouldn’t be very far from having a communication.


More information about the Gdb mailing list