Subject: Re: NetBSD/i386 and single board computers
To: Greg A. Woods <firstname.lastname@example.org>
From: Mary Rivett <email@example.com>
Date: 12/04/1997 11:52:02
On Wed, December 3, 1997, Greg Woods wrote:
> I'd be interested in hearing if anyone has done any work with NetBSD on
> any of the PC104 boards too....
We have been running NetBSD on a PC/104 ISA embedded system for some time
now. The stack consists of 1) an AMPRO 486/DX cpu board running at 66 Mhz,
with 8 meg RAM; 2) a MESA 4i29 10-BASE-T ethernet card; 3) an RTD dm-5416
16-bit 16-channel A/D card; and 4) 3 custom cards for interfacing to
custom hardware for measuring microgravity acceleration values. The
system has no disks (floppy or hard) - it boots remotely from a server
(also running NetBSD). For testing in the lab, we add an AMPRO video card
to the stack; otherwise the target system is headless as well as diskless.
As for what we had to do special:
Early on in the project, we connected an IDE drive to boot from until
we got the code in the .../netboot directory working. Then we put that
in an EEPROM on cpu board. We also wrote 2 custom drivers - one for the
RTD card and one for the acceleration measurement cards - without too
much grief. (The one for the custom cards uses DMA, so it was a bit
harder.) We recently (this past summer) ported all of our additions
(netboot and the 2 drivers) to 1.2.1. with minimal effort. If you aren't
doing anything unusual, like remote booting or using custom hardware,
you probably won't need to do anything special to get NetBSD running
on a PC/104 architecture. Actually, I guess I can only say that about
ISA PC/104 - I don't know about PCI PC/104.
Our application software is still under development, but so far the
performance is good. We are constrained by power and thermal requirements
to no more than 8 meg RAM and no greater than 66 Mhz on the cpu speed,
but that seems sufficient for what we have to do. Actually, before we
upgraded from 1.1 to 1.2.1 we were running satisfactorily with 4 meg RAM.
We have always used a 32 meg swap file on the server.
In general, our experience using NetBSD for this project has been good.
Hope this answers some of your questions...
Mary L. Rivett NASA-Lewis Research Center
firstname.lastname@example.org Cleveland, OH