Re: Protocol Translation (Apologies for LONG email)

Ramana Radhakrishnan
2004-02-11T13:33:01Z

>
> Method 1) Add a new target, e.g. remote-rvi.c or something.
>
> There's nothing wrong with adding a new target except I can see myself
> running into problems with the functions I've coded. I need to connect
> to the RV-ICE in a certain way and also to build/send/receive/decode the
> RV-MSG messages in a certain way. As far as I can see, this is simply
> not directly compatible with any of the GDB functions because my
> remote-rvi.c file would need complete control to:
>
> Establish a connection to the RV-ICE.
> Connect/Disconnect to the target through the RV-ICE.
> Download a program through the RV-ICE to the target.
>
> Can I have this control from just one remote-rvi.c (type) C file?
>
> It would also mean wading through the C hierarchy in order to determine
> which GDB functions I need to accomplish the various commands. This
> looks like a lot of work at this stage as (respectfully) the development
> documentation for this type of thing is poor, and I'm having to figure
> it out by trawling through the C structure, to see where various
> functions are actually defined in order to work out what they're
> actually doing.
>
> In addition to this, there is no real protocol translation going on -
> more "C-function" translation which is not really the idea. Anyway,
> what are your thoughts on this one?
>
> Method 2) Use 'remote tcp' with some kind of switch and
> capture/translate the RSP messages before they go out on the
> Ethernet.
>
> I'd need to find out where exactly GDB constructs it's RSP message
> before it sends it out down the Ethernet and capture it before it goes.
> I think this would involve something like checking the command line
> switch and changing the read/write functions in ser-tcp.c and/or
> ser-unix.c to write/read their messages to/from my own translation
> function.

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

HTH

cheers
Ramana

----
Ramana Radhakrishnan
GNU Tools
Codito Technologies