[U-Boot] NAND on Davinci boards

[Stefano Babic]

On 03/16/2011 01:12 PM, Nick Thompson wrote:
> You may be correct, but maybe you have another problem first...

Yes, you are right...

>>
>>>
>>> Have you tried "nand dump" of a Linux programmed Kernel and compared it with
>>> "nand dump" of a U-Boot programmed Kernel?
>>
>> I have tried now to get the first page (=2048 bytes) from both and I
>> have compared byte-per-byte. They are identical, inclusive the oob part.
>>
>>> You would be able to see
>>> identical data in each case, but you will be able to compare the differences
>>> in the OOB. You only need to look at the first page to see if the OOB data
>>> or position of the OOB data differs.
>>
>> No differences at all. For both, I get in the oob:
>>
>> OOB:
>>         ff ff ff ff ff ff ff ff
>>         ff ff ff ff ff ff ff ff
>>         ff ff ff ff ff ff ff ff
>>         00 00 00 00 00 00 00 00
>>         00 00 00 00 00 00 00 00
>>         00 00 00 00 00 00 00 00
>>         00 00 00 00 00 00 00 00
>>         00 00 00 00 00 00 00 00
> 
> Is this really from the OOB for the first _kernel_ page. It looks wrong.

Yes. this is when I write the kernel from linux.

> 
> I see:
> 
>> nand dump 0x100000
> <snip>
>         ff ff ff ff ff ff ff ff
>         ff ff ff ff ff ff ff ff
>         ff ff ff ff ff ff ff ff
>         9a ea 40 97 85 bc 5f f5
>         2e 15 91 c2 c6 93 14 c0
>         03 e3 b6 4c 35 40 2d 8f
>         7e 74 10 13 59 47 cf 09
>         24 10 6a 0a 8b e2 f1 b0
> 
> The part after all the ff's is the ECC. IIRC a zero ECC implies all the
> data in the page is zero also. That would be an odd start to a Kernel
> image.
> 
> Can you confirm what it is you dumped?

Yes. This
However, when I write the kernel with u-boot, I get:

OOB:
	ff ff ff ff ff ff ff ff
	ff ff ff ff ff ff ff ff
	ff ff ff ff ff ff ff ff
	a7 af c5 ed 87 86 2f 1c
	f9 31 10 92 4a 34 5a 7d
	91 cf e0 fd b6 3f 4b ae
	ca 63 86 9c 2d 91 d2 6c
	95 73 1b 4b e0 09 ed a3

It looks like Linux has not written the ECCs at all....

Stefano

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