Subject: Re: More info re: U3
To: Dave J. Barnes <email@example.com>
From: Steven M. Bellovin <firstname.lastname@example.org>
Date: 09/18/2006 16:03:11
On Mon, 18 Sep 2006 14:11:29 -0500, "Dave J. Barnes"
> >> I didn't know that you could write to the CD-ROM part of the U3. Investigating.....
> > I don't know how one does, but the contents get there somehow, and I'd
> > hate to have to find a Windows machine to use as an SDK platform.
> I do not know what the USB command structure is for telling the existing
> firmware how to divide the FLASH cells up for
> R/W and CDROM. USB sniffer anyone? After many complaints, U3 made a
> utility available for erasing and/or updating the CRROM like partition.
> For Windows only of course:(
> There is no need for a special FLASH FileSystem since the U3 cpu does
> FLASH write wear-levelling, ie.
> "When a file must be updated, TrueFFS does not overwrite the old
> data. Instead, it writes the new data to unused blocks and directs
> subsequent read accesses to these blocks. The old data is marked as
> "old", and is not erased until the block has to be reused."
> Hmmm. You could run an O/S on the U3 without fear of wearing out a FLASH
> cell. No rotating disk drive needed.
That in itself is cool -- I hadn't noticed it.
> Since the Sandisk U3 (oem == M-Systems mDrive
> http://www.m-systems.com/site/en-US/Support) has an ARM7 CPU it could
> run an embedded version of NetBSD.
> Wouldn't that be weird! Get those hackers warmed up:) (I wonder how much
> RAM and FLASH ROM the ARM7 CPU has.)
For that, I've been looking at BlackDog
(http://www.projectblackdog.com/), which runs Debian Linux.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb