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From: Peter Dufault <dufault@hda.com>
Message-Id: <199612191017.FAA24792@hda.hda.com>
Subject: Re: embed
In-Reply-To: <Pine.BSF.3.95.961219070900.340A-100000@localhost> from abc at "Dec 19, 96 07:13:48 am"
To: abc@alaska.net (abc)
Date: Thu, 19 Dec 1996 05:17:14 -0500 (EST)
Cc: questions@freebsd.org
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> 
> does anyone know of anything about "embedded" (romed) UNIXs ?
> 
> i saw Linux had a project - but nothing working (ELKS) ...
> 
> is FreeBSD ROMable ?  anyone ever try it ?
>
> or is the idea ridiculous?

No

> or any other advice on a portable ROMable standard ?

Visit QNX.com for a product from an established company (not a sales
pitch - a pointer).

> 386 CPU ok - but NO drives (moving parts) ...
> 
> no sales pitches please!
> 
> i also hear that writing device drivers can be a real pain in the butt for
> UNIX (A2D cards, etc) ?  any comments ?
> 

For a stand-alone system you'll need a lot of ROM (guess 2 MB) and
you'll need memory for a memory file system.  As an unprofesional
guess I'll say a 2MB compressed boot ROM and 8MB RAM (4MB memory
4MB MFS) would work for many applications.  The right thing to do
is to prototype with a boot floppy and see what the real footprint
is.

Something that will have a lot of applicability is a small system
that boots off a network with network updateable FLASH and optional
full boot FLASH.

I realize this isn't what you have in mind, but I think we should
stake out the VAX-11/750 configuration (4MB RAM, 128 MB NV storage,
good network support) and aggressively ride the constant-performance
curve.  What will that cost in two years?.

Those final two are my working thoughts about minimal systems:
network boot FLASH and "VAX-11/750" (I think of it as .750 FreeBSD).

Writing device drivers for A2D cards etc needn't be a pain if you
have the docs and we modularize the existing ones a bit more.  For
the type of system you have in mind I doubt there is much of a
driver.

-- 
Peter Dufault (dufault@hda.com)   Real-Time Machine Control and Simulation
HD Associates, Inc.               Voice: 508 433 6936