[U-Boot] "nand biterr" ... got an implementation?

[U-Boot] "nand biterr" ... got an implementation?

[David Brownell]

I was hoping that I could use that to test some NAND code, but
then I noticed it wasn't implemented.  I would have expected that
U-Boot command wouldn't exist until they're implemented...

I'm hoping someone has an implementation.  With at least these
characteristics:

 - Doesn't toggle the same bit each time
 - Repeating N times on a block introduces N distinct 1-bit errors
 - Normally affects only the data area, not spare/OOB
     * although forcing bit errors in ECC would be valuable too
     * ditto the rest of the OOB ... though likely they'd be ignored

Am I hoping in vain?  ;)

- Dave

[U-Boot] "nand biterr" ... got an implementation?

[Scott Wood]

On Tue, Apr 21, 2009 at 07:38:27PM -0700, David Brownell wrote:
> I was hoping that I could use that to test some NAND code, but
> then I noticed it wasn't implemented.  I would have expected that
> U-Boot command wouldn't exist until they're implemented...

Sorry about that. :-(

It probably existed in an older version of the NAND code, and never got
reimplemented.

> I'm hoping someone has an implementation.  With at least these
> characteristics:
> 
>  - Doesn't toggle the same bit each time
>  - Repeating N times on a block introduces N distinct 1-bit errors
>  - Normally affects only the data area, not spare/OOB
>      * although forcing bit errors in ECC would be valuable too
>      * ditto the rest of the OOB ... though likely they'd be ignored

A general write-to-oob command would be nice as well.

-Scott

[U-Boot] "nand biterr" ... got an implementation?

[David Brownell]

This is still in my mailbox, don't know that I'll get around to
it any time soon, but another requirement came to mind.


On Wednesday 22 April 2009, Scott Wood wrote:
> On Tue, Apr 21, 2009 at 07:38:27PM -0700, David Brownell wrote:
> > I was hoping that I could use that to test some NAND code, but
> > then I noticed it wasn't implemented.  I would have expected that
> > U-Boot command wouldn't exist until they're implemented...
> 
> Sorry about that. :-(
> 
> It probably existed in an older version of the NAND code, and never got
> reimplemented.
> 
> > I'm hoping someone has an implementation.  With at least these
> > characteristics:
> > 
> >  - Doesn't toggle the same bit each time
> >  - Repeating N times on a block introduces N distinct 1-bit errors

     - Needs to reflect ECC structure.  That is, when a 2K page is
       split into four distinct 512-byte ECC regions (plus OOB),
       it must be possible to force e.g. four errors in the second
       region while leaving the others alone.

> >  - Normally affects only the data area, not spare/OOB
> >      * although forcing bit errors in ECC would be valuable too
> >      * ditto the rest of the OOB ... though likely they'd be ignored
> 
> A general write-to-oob command would be nice as well.
> 
> -Scott
> 
>