[Yaffs] Re: YAFFS and HW ECC

[Wookey]

+++ Roberts Nathan-mcg31137 [05-03-09 14:41 -0600]:
> 
> I have a question regarding HW ECC and YAFFS.

> If a hardware ECC implementation automatically updates ECC bytes in the
> spare area yet those bytes conflict with the tags that YAFFS places in the
> spare area, it seems like I'm out-of-luck as far as utilizing HW ECC.

> Am I really out of luck or can minor modifications be made to the YAFFS
> usage of the spare area to avoid the conflict thus allowing me to use the
> hardware's automatic ECC capabilities?

I haven't seen a response to this so here goes. There is the old MTD way of
doing this and the new. The new way allows arbitrary positioning of the bits
of info in the OOB as I understand it, which solves your problem. The old
MTD scheme allows 2 or three different schemes but if your hardware is
putting in 'completely' the wrong place then yes you areout of luck without
some hacking.

My understanding is a bit vague. Thomas will no doubt correct me if I'm
talking rubbish. I'mnot sure when the new scheme came in.

The above applies if using YAFFS with Linux and the MTD layer - maybe you
aren't?

If using YAFFS alone then I'm not sure how hard it is to rearrange the OOB
layout, beyond the options provided in the config. 

Wookey
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