[ECOS] NAND Device driver with HW ECC

[Ross Younger]

On 09/02/11 17:58, harish kasiviswanathan wrote:
> I would like to know if someone has a ported the NAND device driver to
> MX27 ADS board. MX27 Nand flash controller has HW ECC unit. I would
> like to use it. Can someone please let me know the complexity of this
> porting?

The complexity of a port depends on:
- how similar the NAND flash part is to those for which drivers already 
exist
- how similar the flash controller and ECC unit are to existing drivers

> My concern is the usage of spare area. HW ECC takes a few bytes from
> the middle of the spare area. Does YAFFS / NAND device driver require
> the whole spare area? How to configure this?

YAFFS only needs 25 bytes of spare per NAND page.

If you're using the eCosCentric NAND library, use of the spare area is 
configured during the porting process and you get to specify exactly 
which bytes from the spare area are available to YAFFS or other 
applications. I believe Rutger Hoffman's NAND library is similar.


Ross

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