Re: Protocol Translation (Apologies for LONG email)

[Andrew Batchelor <A dot C dot Batchelor-99 at student dot lboro dot ac dot uk>]

Hi Ramana,

Thanks for your reply...

On Wed, 2004-02-11 at 13:45, Ramana Radhakrishnan wrote:
> ser-tcp , ser-unix.c just add the communication interfaces to gdb
> depending on the underlying communication to the debug monitor . I assume
> that your RVICE box can be reached through the ethernet / serial cable. So
> any communication based stuff is already in there.

Ah, I see.  The RV-ICE box can be reached through the ethernet, but it
has to be setup and initialised before any communication can occur with
the target.  With regard to ser-tcp.c, I was wondering whether I could
just point the functions in '_initialize_ser_tcp' to my own translating
functions, e.g.

  ops->readchar = rvmsg_2_rsp_read;
  ops->write = rsp_2_rvmsg_write;

But I see what you're saying.

> What you need to be doing is to add your own target implementing the
> members of the target structure that rv-ice will support for you.
> 
> For e.g. if you look at remote.c you can see functions like 
> remote_insert_breakpoint in remote.c which actually constructs the 
> packet to be sent out and then calls the underlying putpkt to do the 
> actual communication to the target. What you might consider doing is 
> just simply set up the remote protocol details for your RVICE ? The 
> protocol details like the command to insert a breakpoint, etc. etc.

So I'd have a file called remote-<something>.c (or would add to
remote.c) containing all the relevant functions for RV-MSG communication
(similar to the cisco stuff).  So I could have my own:

	remote_rvmsg_open,
	remote_rvmsg_close,
        .....
	remote_rvmsg_fetch_registers functions etc.

And would only need to concern myself with getting the relevant info
back to GDB via the "serial_write" function (Line 5747, remote.c)?

I'd then have to link all the used functions via something like:

	remote_rvmsg_ops.to_open = remote_rvmsg_open;
	remote_rvmsg_ops.to_close = remote_rvmsg_close;
	.....
	remote_rvmsg_ops.to_fetch_registers =
			remote_rvmsg_fetch_registers,  etc.

And then push the newly made target into GDB before using it:

	push_target (&remote_rvmsg_ops);

Does this sound (very) roughly correct?

> So option 1 is the correct one. IMO option 2 does not seem valid.

Okay, thank you for all the info.  What do you think of Bill Gatliff's
idea of creating my own gdbserver-type proxy program?  How do you think
it compares?


Andrew