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Re: GDB 5.0 works only at 9600 bps?


Jens-Christian Lache wrote:
> 
> Hi Fernando!
> I did use the the -b option (see below). I just wanted to show
> with the first lunch of gdb that it works on 9600bps. In the second
> it gets started with -b 115200. It always hangs with a different
> speed than the default speed.
> 
> I have seen 57600bps under win/multi (gr**nhills inc.) with
> my ATEB01, so it is not the board.
> 

This is the same board as I have.  It seems to be a board monitor bug
When GDB sends the option list (as specified in the ARM document that defines
the protocol), this board replies with some speed (I don't think it is 115200
though) but it does not seem to switch to that speed as promised because GDB
does switch to the indicated speed and cannot communicate with the board
anymore.

As the RDI protocol requires that the handshake starts at 9600, you have to
reset the board so it falls back to that speed before being able to connect
again.

All this can be seen by turning the log on:

(gdb) maintenance rdilogfile /dev/tty
(gdb) maintenance rdilogenable yes 


The software you mentioned probably added a hack to work with this board
but I had no time to experiment with it to figure out what is the speed that
it actually switches to. And I am not sure how I could add something that 
would work with this board without violating the protocol and making GDB
stop working with the other well behaved boards (we have many Angel monitor
targets that speak RDI correctly and switch speeds perfectly).


I will be interested in finding a way to get this to work somehow (I have
the little AEB board).  You can help by getting the handshake messages log.
We may even ask ARM about this (maybe some undocumented protocol extension?
A new version of the monitor is available?).


Regards,
Fernando





-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9

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