dangerous NAND_BBT_SCANBYTE1AND6

[Ivan Djelic]

On Wed, May 25, 2011 at 07:04:40PM +0100, Atlant Schmidt wrote:
> Ivan:
> 
> > <digression> ...
> > And recent Micron devices do not store markers in flash; they just
> > return 0x00 for any byte read in a bad block (instead of the real
> > data), using an internal bad block table.
> > </digression>
> 
>   Does this mean that it is impossible to mark additional
>   bad blocks in these devices as blocks go hard-bad during
>   use? Or do commands exist to extend the internal bad
>   block table? (And do our MTD drivers know how to do that?)
> 

Note that the usual bad block detection still works on those Micron devices.
They just do not store markers in flash.

You can still mark a block gone bad either by writing your own marker into the
block or (better) in a separate BBT. The internal Micron table is hard-wired
and only used to shortcut access to factory bad blocks AFAIK.

Regards,

Ivan