Re: [ECOS] GDB question.

[Gary Thomas <gary at mlbassoc dot com>]

On Fri, 2004-02-06 at 23:15, Ottawa Guy wrote:
> Hello,
> I am very new at implementing GDB stuff. I have
> simulator which can a talk to a GDB host software
> throught a serial port. I loaded GDB stubs in my
> simulator and called "breakpoint()". 

What kind of simulator is this?  Who wrote the GDB stubs that
run on the simulator?

> 
> I start my gdb host program, and type the following
> 
> (gdb) target extended-remote /dev/ttyS0
> Remote debugging using /dev/ttyS0
> Couldn't establish connection to remote target
> Malformed response to offset query,
> T0544:00000000;0e:00000000;
> (gdb) 
> 
> 
> I found the GDB host was sending "+$Hc-1#09" to my
> target.
> 
> It seems my GDB stub program keep on sending
> "T0544:00000000;0e:00000000" string I have no idea
> why.

This is an indication from the remote system that it has stopped, 
probably abnormally.  It most likely means that your stubs are not
working properly.  The fact that the values are 0 also implies that
there is something wrong at the other end.

> 
> 
> Can someone let me know what are the sequence of
> events suppose to happen at the target when  the GDB
> host request for a connection. By that I mean when the
> GDB host type "target extended-remote /dev/ttyS0" what
> should be the sequence of response expected from the
> target.

The actual request/reply script will differ from platform to platform
and architecture to architecture.  To understand this completely, you'll
need to read about the GDB remote protocol.  If you are running Linux,
you can get a very complete description from "info gdb"

Gary Thomas <gary@mlbassoc.com>
MLB Associates


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