[U-Boot] Need help to get u-boot running on the taskit stamp9g20

[Markus Hubig]

On Thu, Jul 12, 2012 at 11:28:13AM +0200, Andreas Bießmann wrote:
> On 11.07.2012 21:28, Markus Hubig wrote:
> > as part of my bachelor thesis I'm working with the stamp9g20 / portuxg20
> > board from taskit (http://www.taskit.de/produkte/stamp9g20/index.htm). I
> > have a patch for a older version (2010.somewhat) of u-boot to get it running
> > on this board, but this patch is not working anymore.
> 
> well, there where a lot of architectural changes (renames, drop of old
> code, ...) in at91 around 2011. This is still work in progress, however
> nothing happened since Reinhard gave up. I hope to bring this to an end
> this year.

Hmm, is there some documentation I can about the changes?

> > Now I'm in the process of adapting this patch to the new u-boot. Up to now
> > I can compile a u-boot.bin and download it to the board. But after starting up
> > the new u-boot I just see this on the serial port
> > 
> > ---8<------------------------------------------
> > U-Boot 2012.04.01-00001-gadcb359-dirty (Jul 11 2012 - 19:24:58)
> > 
> > CPU: AT91SAM9G20
> > Crystal frequency:   18.432 MHz
> > CPU clock        :  396.288 MHz
> > Master clock     :  132.096 MHz
> > DRAM:  64 MiB
> > WARNING: Caches not enabled
> > NAND:  RomBOOT
> > ---8<------------------------------------------
> 
> So something went wrong in nand_init()? Two things you should do:
>  a) as Wolfgung suggested previously: disable the Watchdog

Is this something I can do within my u-boot configuration file? Like so:

#undef CONFIG_AT91SAM9_WATCHDOG
#undef CONFIG_HW_WATCHDOG

>  b) check for the 'NAND Ready' Pin (use some oscilloscope);
>     alternatively just remove the CONFIG_SYS_NAND_READY_PIN R/B should
>     be handled by the nand_base driver in another way then.

Hmm I have the PortuxG20 (mini PC) so I'm not sure if I have access to
this pin ... will check this.

> > and the board is rebooting every some seconds. I'm not able to give it some
> > input via the keyboard. I think maybe there are just some small bits missing
> > but I'm a bit lost now ... maybe some of you can have a look and can give me
> > some advice. ;-)
> 
> enable debug for all the drivers/mtd/nand files, put in some more debug
> printouts where necessary.

Is there a "#define DEBUG" kind of thing?

> > I include the old patch (portuxg20.patch) and the three patches I made in this
> > email. My patches are based on u-boot v2012.04.01.
> 
> Please send the patches in line, Wolfgang already sent a pointer
> describing ho to achieve this.

Ups got a bit lazy these days with emails, but I resurrected my good old
mutt so there will be no more "faux pas" ... ;-)

> Another not related question: What is your Bachelor thesis about? Is
> there some space to implement some basic SPL for u-boot on at91?

My thesis is about to build a small embedded linux logger device on top of
the stamp9g20 platform. But more generally it's about making a starting point
and getting some experience for further embedded linux development in my
company.

With SPL you mean a "Second Program Loader"? Is this intended to replace the
AT91Bootstrap?

Generally I can't answer your question by now, since I know to little about
the u-boot ... my first goal is to get a running u-boot and the stamp into
mainline.

> I'm looking forward to get proper patches for the stamp9g20 to have this
> device mainlined. Unfortunately Taskit has not tried to bring their
> devices to mainline in the past. Therefore I think this would be your
> task if you (or the company you working for) want this device supported
> by u-boot mainline code. I don't want to summarize all the advantages,
> you just hit one problem of out of tree code ...

I'm in contact with taskit, but since there newer boards don't use u-boot
it's not in there main focus to get there boards mainlined ...

Many thanks,
Markus