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