[9fans] ipaq / flash filesystem question

[9fans] ipaq / flash filesystem question

[steve-simon]

Hi,

I understand the iPaq uses a flash filesystem as its backing store
but from a cursory glance at the source indicates this is prepared
on another plan9 box and downloaded as a memory image - maybe this
is just for bootstrapping?

My question is: can the plan9 flash filesystem read and write files?
and seccondly does it know about wear leveling?

If so I shall be re-reading the Licience to see if I can use it for
a product proposal...:-)

-Steve

Re: [9fans] ipaq / flash filesystem question

[David Presotto]

there are 2 different file systems.  One is the read only one you
mentioned.  The other is a log structured one that brucee wrote
that is r/w and really well suited for flash, called brzr.  I thought
there was a man page for it but I can't find it.

Re: [9fans] ipaq / flash filesystem question

[David Presotto]

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Look /sys/src/cmd/cmd/aux/flashfs for the flash r/w file system.
I'll build a man page if I can't find one.

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From: David Presotto <presotto@closedmind.org>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] ipaq / flash filesystem question
Date: Thu, 6 Nov 2003 12:15:02 -0500
Message-ID: <51426fcb577bc037da9c57d968de2f0a@plan9.bell-labs.com>

there are 2 different file systems.  One is the read only one you
mentioned.  The other is a log structured one that brucee wrote
that is r/w and really well suited for flash, called brzr.  I thought
there was a man page for it but I can't find it.

Re: [9fans] ipaq / flash filesystem question

[C H Forsyth]

>>that is r/w and really well suited for flash, called brzr.  I thought

it's good code.  it's better for NOR flash;
for NAND it's not so clear cut, although
if you're happy with the resulting trade-offs,
a buffering NAND driver might get you going.

Re: [9fans] ipaq / flash filesystem question

[Charles Forsyth]

>>it's good code.

by which i mean that it's well worth reading even
if you never intend to flash

Re: [9fans] ipaq / flash filesystem question

[Bruce Ellis]

i'm not totally to blame, the design is presotto's - simple enough
to be explained to me over first coffee of the day.  the limbo
version has been used solidly for two years and has a few
enhancements / bug fixes.  it's mild on the flash but *please
don't use it for log files*.  i'll update the C version if it is in use.

brucee
----- Original Message -----
From: "David Presotto" <presotto@closedmind.org>
To: <9fans@cse.psu.edu>
Sent: Friday, November 07, 2003 4:15 AM
Subject: Re: [9fans] ipaq / flash filesystem question


> there are 2 different file systems.  One is the read only one you
> mentioned.  The other is a log structured one that brucee wrote
> that is r/w and really well suited for flash, called brzr.  I thought
> there was a man page for it but I can't find it.