[U-Boot] Fwd: [PATCH v4] arm: omap3: Add SPL support to cm_t35

[Stefan Roese]

Hi Nikita!

(Added Pekon to Cc)

On 03.12.2013 17:07, Nikita Kiryanov wrote:
> Hi Stefan,
> 
> On 11/27/2013 12:05 PM, Stefan Roese wrote:
>> Hi Nikita!
>>
>> On 27.11.2013 10:46, Nikita Kiryanov wrote:
>>> I compiled SPL with your patch and it does boot U-Boot from an SD card.
>>> U-Boot functionality seems to be intact too.
>>> However, I was unable to install it on the NAND flash. When booting
>>> from NAND, SPL does start (the SPL header is displayed), but it fails to
>>> load U-Boot with the following errors:
>>>
>>> Error: Bad compare! failed
>>>
>>> I used similar commands as the ones I use to install X-Loader:
>>> CM-T3x # mmc rescan && fatload mmc 0 80a00000 mlo && nandecc hw && nand
>>> erase.chip && nand scrub.chip -y && nand write 80a00000 0 30000
>>> CM-T3x # fatload mmc 0 80a00000 u-boot.img && nandecc sw && nand erase
>>> 80000 60000 && nand write 80a00000 80000 60000
>>>
>>> Perhaps some of the recent changes regarding NAND ECC messed things up?
>>
>> Might be. I have not tested the latest U-Boot version on this board yet.
>> The last version I did test was:
>>
>> 63c4f17b2f8017d22241522a48c765073b8791b0
>>
>> Author: Nikita Kiryanov <nikita at compulab.co.il>  2013-10-16 16:23:29
>> Committer: Anatolij Gustschin <agust at denx.de>  2013-11-12 10:12:07
>> Parent: f109a6e73e6bf177eabedfa5fb622ed4809e145c (omap3_dss: define DSS_ONOFF)
>> Child:  3f0b8b4da58c702c92652981a1e563c129108316 (arm: omap3: Add SPL support to cm_t35)
>> Branches: cm-t35-2013-11-15, cm-t35-2013-11-26, dxr2-v1, master, remotes/origin/master
>> Follows: v2013.10
>> Precedes: v2014.01-rc1
>>
>>      cm_t35: use scf0403 driver
>>
>>      Use scf0403 driver to add scf0403x LCD support for cm-t35 and cm-t3730
>>      boards.
>>
>>      Signed-off-by: Nikita Kiryanov <nikita at compulab.co.il>
>>      Acked-by: Igor Grinberg <grinberg at compulab.co.il>
>>
>>
>> With this patch attached. Perhaps you might test this version as well.
>> To see if this works for you too.
> 
> I tried the above, but SPL still can't boot U-Boot from NAND. I get an
> SPL header followed by a stream of "Error: Bad compare! failed".
> 
>>
>> I'll try to test with the latest U-Boot version (hopefully) later this
>> week.
> 
> When based on v2014.01-rc1, SPL itself doesn't boot from NAND (no SPL
> header or any visible activity when booting from NAND).

Yes. I have now tested this as well. I have been digging into this a bit
this morning. And it seems that this patch is causing the regression:

d016dc42 [mtd: nand: omap: enable BCH ECC scheme using ELM for generic
platform]

I can only suspect that with this patch applied, U-Boot writes the SPL
(MLO) to NAND in an incompatible way for the BootROM. I have switched to
1bit HW ECC of course.

Very strangely, the Technexion TAO3530 board works fine with SPL. Even
with current mainline. The only difference I can see right now is, that
TAO3530 has an 16bit NAND chip and the CM_T35 has an 8bit NAND chip.

Unfortunately I have to stop debugging this issue now. Perhaps Pekon has
an idea on whats going on here. Pekon, do you have an OMAP3530 board
with an 8bit NAND chip? Or do you have any other idea, what might cause
this problem?

Thanks,
Stefan