On Tue, 11 Apr 2000, David Woodhouse wrote:
>> > Does this sound like the sort of flash that is supported ???
>
>alan@lxorguk.ukuu.org.uk said:
>> No
> ...t out of the box.
>
>I had Datalight stuff working in Linux about three years ago - my work back
>then is what the current MTD code is based on. That was actually on the
>DiskOnChip 1000 and the M-Systems ISA flash boards.
>
>I haven't actually had any such hardware recently but the code is still
>there. They're almost certainly still using FTL on it, and if not we can
>stick Axis' new flash filing system on it.
>
>If someone sends me such a box, I'll try to make sure it still works.
>
>> 1. The DOS drivers wont hekp you using a real OS
>> 2. Wear levelling is meshed in a myriad of mostly stupid patents so
>> adding your own support gets you a product that gets you sued in the
>> USA.
>> 3. The linux fs's dont work well on flash
>
>1 will remain true unless you use a huge initial ramdisk, but Axis is
>working on 2 and 3.
>
>
>alan@lxorguk.ukuu.org.uk said:
>> Also worth knowing is SANdisk compact flash looks like ide and works
>> well on Linux.
>
>CF devices have to do their own journalling on the flash internally, in
>order to be reliable.
>
>If you're putting CF in an embedded device, you almost certainly want to
>stick a journalling filesystem on top of that. This means you have two
>layers of journalling on top of each other - hardly an efficient use of the
>hardware.
>
>Using FTL or NFTL on flash presents the same problem - that's why I've
>been saying for ages that we need a filesystem which runs directly on the
>flash, and why I was so pleased when Axis developed one.
> http://developer.axis.com/software/jffs/
>
>Note that current wisdom is that JFFS doesn't actually violate any of the
>insane patents on wear levelling. Although it does sometimes set '1' bits
>to '0', which I believe is also a patented technique.
Hi!
I replied privately to the original poster (Lee Mitchell) telling him about
M-Systems ( http://www.m-sys.com/ ) and their products. They've got the
DiskOnChip 2000 series product which you can stick onto the ISA bus with two
logic ICs and some resistors (more or less) and I've also seen ready-built ISA
cards with these chips, dunno if it was on their site though.
Anyway, they've made some sort of FS as well;
<quote src="http://www.m-sys.com/product.asp?PID=2FILE=doc2k&FAM=doc">
TrueFFS
The DiskOnChip 2000 includes M-Systems' proprietary TrueFFS® (True Flash File
System) technology built-in, providing complete read/write capabilities and
hard disk emulation. TrueFFS provides hard disk compatibility at both the
sector and file level. The DiskOnChip 2000 works in all major operating
systems including DOS, Windows 95/98/2000/CE/Embedded NT, pSOS+, VxWorks and
QNX. It can also be easily customized to work in O/S-less, or non-x86,
environments.
</quote>
They've got 2.0.x and 2.2.x block drivers as well. I'll most proably end up
using DOC2000 with Linux in an embedded system I'm building.
I don't know if this is at the same level as Axis' FS, but I really liked
M-Systems' products.
//Peter
-- irc: CareBear\ tel: +46-40-914420 irl: Peter Stuge gsm: +46-705-783805- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
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