[Yaffs] Re: YAFFS, DOC - newbie questions

[Wookey]

+++ Sudeep Jain [04-10-14 16:43 -0700]:
> hello,
> 
> >From these requirements, it appears that the M-Systems
> Disk on Chip devices are the best, as they are
> supported by MTD (are they ?), they hook up into a
> standard IDE interface, dont emulate a hard disk, and
> hopefuly (at least the larger disk sizes) have
> multiple flash chips inside which I can then access in
> parallel.

But all DOC devices contain a controller so you are not talking directly to
the flash, but to a controller, which, if I understand correctly, runs
M-system's TrueFFS filesystem on the flash.

So you can't use your own filesystem on these devices.

I may be confused about this, but that's the impression I got from an
M-systems rep I talked to today.

> Questions
> 1) Can the DOC devices be changed to allow access by
> the host system at a (chip, block, page) level ?

I don't think so.

> 2) Do the MTD drivers work with DOC devices, and can
> they provide this level of access ?

I think there is MTD support for DOC, but I don't understand how this fits
with my understanding that you have to use TrueFFS.

> 3) Do the MTD devices have multiple NAND chips inside

Some DOCs will have multiple devices, as do some CF cards.
MTD supports multiple devices which can be accesed individually or as a
merged device.

As Charles says you will get more accurate answers on the linux-mtd list
(@infradead.org)

Wookey
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