[U-Boot-Users] Command line parsing question

[Wolfgang Denk]

Dear Jeff,

in message <1079048468.9835.35.camel at localhost.localdomain> you wrote:
> 
> When I type in commands at the command prompt and hit enter, some of the
> commands are getting run twice.

U-Boot just executes the commands it gets told.

> One thing to note about my setup is that I am accessing the serial
> console using telnet over a remote serial devices server.  So the whole
> telnet end-of-line issue and the processing of CR,LF, and NUL come into
> play.

I know this problem well. I have seen it before. Your terminal server
is misconfigured. We use a couple of terminal  servers  ourself,  and
for example I never got a MAXSERVER running correctly.

> Snooping the network and watching the character counts on the seriver
> server's serial port, I can see that each time I hit <Enter> there are
> two characters going over the serial line (CR-LF or CR-NUL) to the
> target.

Yes, this is what I've seen, too.

> 1) Has anybody else encountered this problem?  I already googled for an
> answer but came up with nothing.

I know this problem all too well.

> 2) Does anybody have any idea why some commands are working and others
> are not?  I would expect that either all would be repeated or none of
> them would be repeated.

U-Boot knows at least 3 different ways to respond to an empty input line:

* after "non-critical" commands like "version": repeat the command
* after "critical" commands like "erase": do nothing
* after some special commands like "md", "mm" etc.: repeat command for
  the next address(es)

In your case, the '\0' character confuses U-Boot.


You can try playing with telnet options (try setting "mode character"
in your telnet session), but you will have to repeat  this  for  each
new session. In my case I never was able to get such a system working
as  intended.  I  finally gave up and bought a different (known to be
working) type of terminal servers.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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