[U-Boot-Users] U-Boot-1.2.0 - NAND bad block management

[U-Boot-Users] U-Boot-1.2.0 - NAND bad block management

[Vaibhav Hiremath]

Hi,

I have ported  U-Boot-1.2.0 to ARM11176 core, which supports NAND
booting (big page NAND device).

I have one query -
How U-boot-1.2.0 handles bad block?
As I understand at the booting time U-Boot-1.2.0 scans whole NAND
device and maintains BBT. This absolutely fine with me, but what will
happen if read operation fails after that, say page read has generated
ECC error. U-Boot-1.2.0 doesn't mark this block as a bad block.

Is this some kind of loop hole in U-Boot NAND support? Since there is
no other cause appart from Write and Erase fail which will mark the
blcok as a bad.
Ideally it should mark that block as a bad for ECC error, since it's
failing of read operation.

Thanks in advance.

Thanks,
Vaibhav

[U-Boot-Users] U-Boot-1.2.0 - NAND bad block management

[Vaibhav Hiremath]

Hi,


Can any one help me out in this issue?

Thanks in advance.


Thanks,
Vaibhav

On 10/3/07, Vaibhav Hiremath <hvaibhav@gmail.com> wrote:
> Hi,
>
> I have ported  U-Boot-1.2.0 to ARM11176 core, which supports NAND
> booting (big page NAND device).
>
> I have one query -
> How U-boot-1.2.0 handles bad block?
> As I understand at the booting time U-Boot-1.2.0 scans whole NAND
> device and maintains BBT. This absolutely fine with me, but what will
> happen if read operation fails after that, say page read has generated
> ECC error. U-Boot-1.2.0 doesn't mark this block as a bad block.
>
> Is this some kind of loop hole in U-Boot NAND support? Since there is
> no other cause appart from Write and Erase fail which will mark the
> blcok as a bad.
> Ideally it should mark that block as a bad for ECC error, since it's
> failing of read operation.
>
> Thanks in advance.
>
> Thanks,
> Vaibhav
>

[U-Boot-Users] U-Boot-1.2.0 - NAND bad block management

[Stefan Roese]

Hi Vaibhav,

On Wednesday 03 October 2007, Vaibhav Hiremath wrote:
> I have ported  U-Boot-1.2.0 to ARM11176 core, which supports NAND
> booting (big page NAND device).
>
> I have one query -
> How U-boot-1.2.0 handles bad block?
> As I understand at the booting time U-Boot-1.2.0 scans whole NAND
> device and maintains BBT. This absolutely fine with me, but what will
> happen if read operation fails after that, say page read has generated
> ECC error. U-Boot-1.2.0 doesn't mark this block as a bad block.

Correct. AFAIK, current U-Boot NAND code, doesn't support bad block marking at 
all.

> Is this some kind of loop hole in U-Boot NAND support? Since there is
> no other cause appart from Write and Erase fail which will mark the
> blcok as a bad.
> Ideally it should mark that block as a bad for ECC error, since it's
> failing of read operation.

Yes, from my understanding this missing bad block marking is a problem that 
should be fixed.

Thanks for bringing this issue up. Now all we need is a patch to support this 
bad block management. ;)

Best regards,
Stefan

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