Re: RDI target broken in 000215 snapshot

[Grant Edwards <grante at visi dot com>]

On Tue, Feb 22, 2000 at 03:36:52PM +0000, Fernando Nasser wrote:

> > The RDI target support seems to be broken in the 000215
> > snapshot.  I'm unable to execute any of the eCos test programs,
> > or any other applictions I've written. (they run fine with a
> > patched-up 4.18 gdb).  I don't know what's wrong with it and
> > won't have time to look at it for a while.
>
> Can you be more specific?  It is working right with the AEB board and
> with another one I have here.  Both use serial ports.

I tried it using the ARM Embedded ICE with serial-only and with
serial-parallel interfaces.  It connects to the device OK, and
I can load a file and set breakpoints, but when I type "cont",
gdb just hangs. Ctrl-C doesn't get any response, and I have to
suspend and then kill gdb.  (This usually means that gdb is
waiting for a response from the JTAG interface box, and it
isn't sending anything.) The exact same sequence of operations
w/ patched 4.18 works (the program runs properly, hits the
expected breakpoint, etc.).

I haven't tried it with the EPI Jeeni.  

I plan on comparing ADP packet logs to see what is different,
but this week is pretty busy and next week I'm going to be at
the Embedded Systems Conference in Chicago.  So I won't get
a chance to play with it for a couple weeks.

> Please let me know what is your host machine, what version of
> tools did you use to build gdb, if on cygwin, which version of
> the dll and, last but not least, what is it that you are
> getting on the console.

Host: Linux-Intel (Vanilla RH6.1 w/ 2.2.12-20 kernel)
 Gcc: egcs-2.91.66 (came w/ RH6.1)

> > Is somebody currently working on the RDI code?  If so, I'll
> > leave well enough alone until the code stabilizes.
> > 
> The usual folks.  You, myself, Thomas, Nick, Jim...  and I build and
> test it at least twice a week.

Odd.

The ADP protocol/code from ARM is pretty fragile.  If the
target doesn't reply to a command, the whole thing sits there
and you have to kill gdb, reset the target, and start over.
Onee could add a receive timeout, but it won't do any good if
the JTAG interface box is hung.  There's also the problem of
the two ends of the ADP connection getting frame sequence
numbers out of sync -- so there may not be a practical solution
other that the current "reset both ends and start over"
approach.

-- 
Grant Edwards
grante@visi.com