From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <20100308154243.GA21591@knaagkever.ueber.net> References: <20100224185312.GA1892@zoidberg.hsd1.mi.comcast.net> <20100308154243.GA21591@knaagkever.ueber.net> Date: Mon, 8 Mar 2010 07:45:21 -0800 Message-ID: <3e1162e61003080745p5d53f822x87815f3fc4ef3748@mail.gmail.com> From: David Leimbach To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary=000e0cd70aece4e49c04814bf3e6 Subject: Re: [9fans] sheevaplug port available Topicbox-Message-UUID: e41d9792-ead5-11e9-9d60-3106f5b1d025 --000e0cd70aece4e49c04814bf3e6 Content-Type: text/plain; charset=ISO-8859-1 On Mon, Mar 8, 2010 at 7:42 AM, Mechiel Lukkien wrote: > 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? > I thought the flashes themselves were doing wear-leveling these days in most products? That's not the case with sheevaplug? Or am I completely off-base? > > 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 > > --000e0cd70aece4e49c04814bf3e6 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

On Mon, Mar 8, 2010 at 7:42 AM, Mechiel = Lukkien <mechiel@= xs4all.nl> wrote:
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<= br> > read or write them hang. =A0I don't know of progress on flash acce= ss or
> anything else.

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

=A0 =A0 =A0 =A0htt= p://code.google.com/p/inferno-kirkwood/source/detail?r=3Dfb12821689bac55890= 75be3049f4a9413d3dfa54

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<= br> 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<= br> and such?

I thought the flashes themsel= ves were doing wear-leveling these days in most products? =A0That's not= the case with sheevaplug? =A0Or am I completely off-base?
=A0

if anyone has tips & tricks for dealing with nand flashes, i'm inte= rested
in hearing them. =A0one question i have: =A0can you read the erase/program<= br> times from the chip? (hard-coding a table with properties based on data
sheets isn't so great). =A0another: my new sheevaplug has samsung memor= y
instead of hynix, so a different vendor id in the chip. =A0but the "de= vice
id" is the same (identifying chip properties (size, voltages, etc)). are those device id's standardized? =A0that would make a hard-coded tab= le
less annoying at least...

mjl


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