[U-Boot] Hangs at relocation on 460EX Target

Stefan Roese sr at denx.de
Thu Oct 23 06:02:30 CEST 2008


On Thursday 23 October 2008, Ayman M. El-Khashab wrote:
> On Wed, Oct 22, 2008 at 07:12:30AM +0200, Stefan Roese wrote:
> > Yes, there have been issues with the "old" autocalibration code on some
> > boards. That's one reason that AMCC provided a new version just a few
> > weeks ago:
>
> Thanks Stefan,  I've got the hardware mostly working now.

Great, congrats.

> The new 
> calibration code did work once I got past another issue.  I'll try to
> describe it here b/c It *might* be a bug, but I wasn't 100% sure.
>
> First, I am using registered ecc dimms which appears to be handled in
> cpu/ppc4xx/44x_spd_ddr2.c

I personally have never used a registered DIMM on the 4xx systems. And I don't 
know of any systems that do. So it could be that this is still untested and 
buggy.

> However, what I found by observing the registers 
> with the abatron was that the SDRAM_MCOPT1_RDEN was not set for the
> registered DIMM. Following the code, it looks like it should have been set
> if "registered" was set, but it does not appear that it worked correctly. 
> So of course we were off by 1/2.  I forced the bit in the mcopt1 variable
> and that fixed all the problems.

Good.

> Any thoughts or is there something I can try/contribute?

Best would be if you could provide a proper patch to fix this problem. Please 
see here:

http://www.denx.de/wiki/view/U-Boot/Patches

how this is done correctly.

Best regards,
Stefan

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