Subject: RE: NetBSD usage in embedded environments
To: Kamal R Prasad <>
From: Justin Wojdacki <>
List: tech-kern
Date: 04/03/2003 10:32:52
On Thu, 2003-04-03 at 07:13, Kamal R Prasad wrote:
> >NetBSD is an excellent operating system... but there are some improvments
> to
> >make it fit better in the embedded space:
> >1. Journaled flash file system
> think a journaled filesystem is a misfit for an embedded device in the
> first place.
> further all the more so on a  flash device which has little space compared
> to a hard disk.

Hmm...seems to work fine for a lot of people. The size of the filesystem
is the biggest issue here. JFFS2 (probably the most popular Linux
journaled flash filesystem) has the unfortunate requirement of 5 free
blocks of flash at any time. So if you have 64KB erase blocks, you can't
use 320KB of your flash device. If you're looking at an 16MB or higher
filesystem, this isn't so bad. If you're trying to be cost sensitive and
stick to 2MB of flash, well, you should look in other directions. That
being said, JFFS2 is decent about limiting the metadata filesystem
consumption, and it compresses all file data written into flash.

Of course, if you don't need a write-able local filesystem, then you
have more options. Or, you could just netboot everything... :)

Justin Wojdacki         (408) 350-5032
Communications Processors Group -- Analog Devices