[Yaffs] Using YAFFS with an array of NOR flash.

Charles Manning Charles.Manning@trimble.co.nz
Wed, 12 Jan 2005 13:44:42 +1300


There is no yaffs on NOR example and I don't really think there needs to
be one.=20
The guys who got this going on a cell phone only needed a few hours or
so to do it.

If you just consider a "chunk" to be a 528-byte bunch of bytes then

Reading and writing a chunk is just reading and writing to the
appropriate offset in a block.



> -----Original Message-----
> From: Michael Erickson [mailto:mikee@logicpd.com]=20
> Sent: Wednesday, 12 January 2005 11:48 a.m.
> To: Charles Manning
> Cc: yaffs@stoneboat.aleph1.co.uk
> Subject: Re: [Yaffs] Using YAFFS with an array of NOR flash.
>=20
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> Charles,
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> Again thanks for the reply. Does any sample code exist for a=20
> NOR device?=20
> Specifically, I'm wondering about the proper handling of=20
> chunks and blocks.
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> - Will a block of NOR flash (in my case 64K) correspond to a=20
> YAFFS block?
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> - When YAFFS calls the function "eraseBlockInNAND()" exported via the=20
> yaffsfs_DeviceConfiguration structure, is it expecting me to erase an=20
> entire block of NOR flash?
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> Thanks,
> 	--mikee
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> Charles Manning wrote:
> > Many people have done YAFFS on NOR and indeed there are=20
> some shipping=20
> > products using this.
> >=20
> > YAFFS does not do erase suspend, so garbage collection is a=20
> bit slow.=20
> > Still, it should be fine for testing purposes. Let's say you have a=20
> > block size of 64kB. Each "chunk" needs 512 data bytes + 16=20
> spare bytes=20
> > =3D 528 bytes. Therefore each block can hold 64K/528 =3D 124 chunks.
> >=20
> > So, set chunksPerBlock to 124 and away you go!
> >=20
> > -- Charles
> >=20
> >=20
> >>-----Original Message-----
> >>From: yaffs-admin@stoneboat.aleph1.co.uk
> >>[mailto:yaffs-admin@stoneboat.aleph1.co.uk] On Behalf Of=20
> >>Michael Erickson
> >>Sent: Wednesday, 12 January 2005 5:29 a.m.
> >>To: yaffs@stoneboat.aleph1.co.uk
> >>Subject: [Yaffs] Using YAFFS with an array of NOR flash.
> >>
> >>
> >>Hello all,
> >>
> >>I am working on integrating the direct interface into our bootloader
> >>environment. Currently, I have read and write capabilities=20
> >>working with=20
> >>the RAM-disk. I want to move on to making the file system=20
> persistent=20
> >>across power-cycles. To do this, I want to try and use an=20
> >>array of NOR=20
> >>flash on my device. We have some NAND flash as well, but I=20
> >>know that the=20
> >>NOR interface is correct, so I want to try it first. Does=20
> anyone have=20
> >>any advice on how to proceed or things to look out for?
> >>
> >>Thanks,
> >>	--mikee
> >>
> >>--
> >>Michael Erickson
> >>Senior Software Engineer
> >>Logic Product Development
> >>(612) 436-5118
> >>mailto:mikee@logicpd.com
> >>http://www.logicpd.com
> >>
> >>
> >>_______________________________________________
> >>yaffs mailing list
> >>yaffs@stoneboat.aleph1.co.uk
> >>http://stoneboat.aleph1.co.uk/cgi-> bin/mailman/listinfo/yaffs
> >>
>=20
> --=20
> Michael Erickson
> Senior Software Engineer
> Logic Product Development
> (612) 436-5118
> mailto:mikee@logicpd.com
> http://www.logicpd.com
>=20
>=20