On Wed, Feb 24, 2010 at 03:22:25PM -0500, geoff@plan9.bell-labs.com wrote:
> usb has advanced a little; we can see usb devices now but attempts to
> read or write them hang.  I don't know of progress on flash access or
> anything else.

in the inferno port i've been able to access the nand flash:

       http://code.google.com/p/inferno-kirkwood/source/detail?r=fb12821689bac5589075be3049f4a9413d3dfa54

that was early code that i committed because my sheevaplug was going
away (i now have a new one with an esata port on it!).

once that code works a better, having a file system on it would be nice.
but i think inferno's logfs and ftl both assume 512 byte pages instead
of 2048 byte pages that the sheevaplugs nand flash has (though it has
writable subpages of 512 bytes), so i'm not sure how hard/easy an fs on
it will be.

does plan 9 have a writable nand flash file system that does wear-leveling
and such?

if anyone has tips & tricks for dealing with nand flashes, i'm interested
in hearing them.  one question i have:  can you read the erase/program
times from the chip? (hard-coding a table with properties based on data
sheets isn't so great).  another: my new sheevaplug has samsung memory
instead of hynix, so a different vendor id in the chip.  but the "device
id" is the same (identifying chip properties (size, voltages, etc)).
are those device id's standardized?  that would make a hard-coded table
less annoying at least...

mjl