[Yaffs] YAFFS on NOR Flash

Charles Manning manningc2 at actrix.gen.nz
Tue Nov 29 21:59:22 GMT 2005


There is no "official" patch for supporting NOR with yaffs. Peter Barada has 
posted a few times discussing NOR, perhaps you could get a patch from him.

While people have had reasonable results with YAFFS and NOR, there is one area 
that can be a bit of a problem: write speed. YAFFS works with the assumption 
that erases are fast (valid for NAND, not for NOR) and does all the erases 
synchronously. This means that writes will "stall" for a while if erasure is 
required (eg. during garbage collection).

There is a possibility to add asynchronous erasure to the YAFFS, but that is 
not a very high priority at present.

-- CHarles


On Tuesday 29 November 2005 21:51, Rudi Engelbertink wrote:
> LS,
>
> A few months back I saw on the mailing list that although yaffs is intended
> for NAND flash, it is possible to use the yaffs filesystem on NOR flash or
> Intel Strata Flash. It was also mentioned that additional info should be
> added to the FAQ. Until now this info isn't available.
>
> My questions is, what needs to be changed/configured to get the yaffs
> filesystem working on the strata flash. The first thing the driver does
> is to check the flash device if it's a nand flash device. Of course the
> strata device isn't, and it exits.
>
> Is there a specific patch for strata (NOR) devices or 'config options' that
> needs to be modified and is it eventually suitable for YAFFS2 ?
>
> Thanks in advance.
>
> Kind regards,
> Rudi.



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