On 06-09-13 19:31 +0400, Vitaly Wool wrote:
> On 9/13/06, Wookey <wookey@aleph1.co.uk> wrote:
>
> >Yes. Yaffs needs to be able to do it's own ECC for YAFFS/direct or
> >indeed any other situation where there isn't something else like MTD
> >to do the work for it.
>
> Oh I see the problem now.
> I think however that the best thing to do here is to use the same
> 'default' OOB layouts MTD uses so that the ECC bytes were placed in
> OOB in the same way. If that solution is fine for you, YAFFS own ECC
> can still be used on most flashes, with some precautions though.
YAFFS internal ECC layout came from compatibilty with smartmedia
layout (IIRC). This is fairly arbitrary (and unfortunately different
to MTD layout). I'm not sure how much aggravation we will cause
existing (non-linux) users by changing it now. I wonder if it is
better to keep the layout as is but simply not use it with Linux 2.6,
or to change to be the same as MTD.
The former avoids Linux problems so long as the docs are clear, and
makes no change for non-linux users.
The latter means linux people can swap between MTD and (slightly
faster?) yaffs ECC easily. But non-linux users will not be able to use
exisiting filesystems with new YAFFS2.
How serious would a non-backwards compatible OOB layout change be for
existing YAFFS2/direct users? Feedback welcome.
Wookey
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