> > 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.
-- dwmw2- 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/
This archive was generated by hypermail 2b29 : Sat Apr 15 2000 - 21:00:15 EST