[Yaffs] OneNAND

[Charles Manning]

I have not read the whole OneNAND spec yet.

On Wednesday 15 June 2005 00:39, Nick Bane wrote:

> > > I note the mtd thread in Feb started by samsung (starting from
> >
> > http://lists.infradead.org/pipermail/linux-mtd/2005-February/01186
> > 0.html). The mood seemed to be to split off OneNAND from generic
> > nand as the access is so different. I was unclear whether this
> > presents OneNAND as non generic NAND mtd technology possibly
> > requiring changes to yaffs eg the test for the device being an
> > "mtd-nand" at mount time.
> >
> > I'm not sure either. I have just skimmed the datasheet, but it might =
be
> > possible to setup a NAND compatible API

You could even set up a NAND interface to NOR if you were really keen :-)=
.

For OneNAND, the sector management might break "NAND-ness".=20

>
> It looks like there are only 2 bytes of user usable data in the "spare"
> area. Although yaffs won't need to do so much ecc it looks like yaffs w=
ill
> have a problem with that little spare space unless one can use bigger
> virtual blocks. Charles?

It might be possbile to subvert some of the other bytes (eg. sector numbe=
r).

I'd be tempted to run this stuff as 2k pages with YAFFS2. That would give=
=20
more bytes/chunk.  Still might not be enough though.


Samsung: If you're reading this, what would ne nice, IMHO, would be the=20
ability to bypass the OneNAND interface and use part of the device as a r=
aw=20
NAND (perhaps with HWECC) for file system purposes and some as NOR equiva=
lent=20
for use as boot sectors etc. Perhaps this is possible.

-- Charles