On Tuesday 12 September 2006 11:17, Andre Renaud wrote:
> When using YAFFS, is it possible to store the tags data in the page
> itself, rather than in the OOB area?

This is not yet implemented but has been identified as something that might be 
worth doing.

> I noticed a discussion a while ago 
> regarding Samsung OneNAND, in which this method was suggested as a way
> of avoiding the restrictions that device placed on the OOB bytes. I have
> a chip with similar restrictions, which I can use fine to store straight
> data in, but not with YAFFS for the filesystem, due (I believe) to the
> OOB issues.

THis would allow yaffs to be used with a far wider variety of media, including 
NOR, USB Mass storage etc.

>
> I assume that a similar method has to be taken when people use YAFFS
> with NOR flash (as has been mentioned in the list).
>
> Has anyone worked on this? Is there a way to force YAFFS meta-data into
> the page area?

Not currently, though it is possible to modify yaffs to do this.

One of the biggest challenges is that this would break power-of-2 page 
alignment (eg. 2k page becomes, say,  2000 bytes of data and 48 bytes of 
tags). Breaking power-of-2 alignment forces more copying and page activity.


-- CHarles