Can not connect to remote stub

[Ormund Williams <ormundw at brainlink dot com>]

Hi

I have built a gdb stub for ARM7 (Sharp's LH77790 on the ARM Evaluation
Board), after burning it into ROM and powering-up the board it responds
with:

    AWT60 eCos
    +$T050f:e8140004;0d:601f0000;#50 <-- this is from a breakpoint set
in an empty forever loop in main() to get gdb's attention.

When I try to connect to the board with arm-elf-gdb I get this:

(gdb) set remotebaud 38400
(gdb) set debug serial 1
(gdb) set debug remote 1
(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
Sending packet: $Hc-1#09...[<Timeout: 2 seconds>]Sending packet:
$Hc-1#09...[<Timeout: 2 seconds>]Sending packet: $Hc-1#09...[<Timeout: 2
seconds>]Sending packet: $Hc-1#09...[<Timeout: 2 seconds>][<Timeout: 2
seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
Ignoring packet error, continuing...
Sending packet: $qC#b4...[-]Nak
Sending packet: $qC#b4...[<Timeout: 2 seconds>]Sending packet:
$qC#b4...[<Timeout: 2 seconds>]Sending packet: $qC#b4...[<Timeout: 2
seconds>][<Timeout: 2 seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
Ignoring packet error, continuing...
Sending packet: $qOffsets#4b...[<Timeout: 2 seconds>]Sending packet:
$qOffsets#4b...[<Timeout: 2 seconds>]Sending packet:
$qOffsets#4b...[<Timeout: 2 seconds>]Sending packet:
$qOffsets#4b...[<Timeout: 2 seconds>][<Timeout: 2 seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
[<Timeout: 2 seconds>]Timed out.
Ignoring packet error, continuing...
Couldn't establish connection to remote target
Malformed response to offset query, timeout

I opened minicom and connected to the stub on my board, [ -> from me, <-
from stub ]

-> +$Hc-1#09
<- +$#00
-> +$qC#b4
<- +$#00
-> +$qOffsets#4b
<- +$#00
none of the above commands I sent are implemented in the stub so it
responds with an empty packet, which is correct behavior according to
the docs.

-> +$d#64
<- +$eCos GDB stubs - built Sep 30 2000 / 12:45:25#18
-> +$M2000,2:ab12#cd
<- +$OK#9a
-> +$m2000,2#8d
<- +$ab12#26
with the above and other commands I can read and write memory and
registers.  The minimum required commands: g, G, m, M, c, and s are
implemented and the stub responds correctly to those commands.

My question is, why does gdb only try Hc-1, qC and qOffsets?

This is just a "load and go" stub.  I have tried gdb-4.18 and 5.0, my
development platform is Linux (Red Hat 6.2).