[U-Boot-Users] Re: Using u-boot as application-firmware upgrader / Performing logical operations?

Wolfgang Denk wd at denx.de
Wed Dec 22 17:23:52 CET 2004

In message <cqc5hl$ajn$1 at sea.gmane.org> you wrote:
> > I already mentioned board/trab/auto_update.c in my message; see  also
> > board/esd/common/auto_update.c
> Ok - so you suggestion is to borrow some code from there and put into my 
> board's init-board functions?

No, I suggested to _look_ what already exists, and then decide if  it
makes  sense  to  use  parts  or more of the existing code, and.or to
combine or replace it by some shell scripts.

> Ohh, of course - that's the way I'll do it. That is, saving it in an 
> environment-variable.
> In order to change it from Linux, access to the NOR-flash is required, 
> right?! I'm not quite sure I have that?

Of course yoiu have - through the MTD layer (and  the  stuff  in  the
tools/env directory).

> Or do I recall correctly, if there was something about having 
> environment in nand, as well?

You can do this, too, if you're really adventurous. I don;t think  it
is a good idea, though.

> Dooh! I forgot that tftp use UDP. Then "responding" means one correct 
> response from the tftp-server within x seconds. I guess there is a 

Define "correct" response. What about time outs later?

> Hence, what I want is perhaps (?) environment variables controlling how 
> how many retries, the interval between each "T"-try, and the amount of 
> tries before abondoning...


> And then a way to check if tftp exited successfully...

You already have that.

> >>Hence, what I'd like, was a way to determine if the download was 
> >>successfull - e.g. by comparing the return value for the command.
> > You can do that easily - just not by timeout only.
> How?

Use the return code in some conditional, like an "if tftp ... ;  then
... ; fi" or some "tftp ... && ..." - whatever you use in other shell
scripts, too.

> Is there a document describing these scripting possibilities?

man sh? Ok, ok, the hush  shell  does  not  provide  every  bell  and
whistle  the  bash  has,  but  it's  a pretty complete thing. See the
busybox docs for more information.

> > tree. So far none of the customers I know of  decided  to  put  their
> > scripts into CVS.
> That's a shame...

Not really.

> >>often have a common denominator - namely serial- and ethernet-connections.
> > Sure. And/or USB memory sticks, or CompactFlash cards, or ...
> Well, yes. But ethernet and serial commands for downloading data is 
> included in as u-boot runtime commands, whereas the others are not (?).

Yes, of course they are.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Don't panic.

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