Re: SuperH DTF connection protocol

[Andrew Stubbs <Andrew dot Stubbs at st dot com>]

On Fri, 17 Aug 2001 tm@kloo.net wrote:

> Andrew Stubbs wrote:
> > 
> > We, here at what will be SuperH, Inc., want to add support for a new
> > target - probably to be called 'sh-elfdtf'.
> > 
> > The DTF (Data TransFer) protocol uses the SH4 (& 5) debug port to allow
> > communication with an embedded target. It is basically the same idea as
> > the GDB trap system currently used in newlib for SH, but also works on
> > silicon
> 
> I'm not a newlib maintainer, but I don't understand why you want to
> put anything into newlib. Newlib is the standard C library. It doesn't
> interface to a debugger in any fashion.
> 
> What did you want to add to newlib?

The standard setup for newlib on the sh (I don't know about other
platforms) is to communicate with the outside world (read, write, open,
...) using a trap. As I understand it this is something understood by the
gdb simulator - it does not work on an actual sh chip and board.

DTF is our protocol for communicating with programs running on real boards
via a network connection through the built in debug link - when running
linux we can use a network card or serial port, but that doesn't work
with hello world.

We want to add support for this to newlib. It just means changing (a copy
of) the sys/sh/syscalls.c file and including a bunch of extra functions.


> BTW, I'm at 179 East Tasman (in the SJ2 building) so if you're in the
> same building, it may be easier to come downstairs and find me on
> Monday.

Er, as the sig says, I think we're probably on different continents. It
would be rather tricky!

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