> Shouldn't be a problem. You can remove so many things from the kernel that
> it practically becomes a task-switcher and IPC layer. Be warned that you
> will probably want to retain a small root filesystem with an /etc directory
> -- many common system facilities rely on configuration files in /etc.
> 
> Unix is only inappropriate for embedded if you have hard requirements for:
>     - memory (under 4 megs)
>     - deterministic interrupt response
>     - deterministic process scheduling
>     - avoiding the use of virtual memory
> 
> An embedded system is really just a complex and specialized server, and Unix
> has lots of history & experience running more general servers such as file,
> print, and database servers.

I run Linux on my embedded PC/104 with 4MB RAM, and it runs perfectly fine. 
I recompiled the kernel without any problems, and lots of diskswapping. 
With the new minimal kernel, there is 1/10 of the swapping.
The datalogger will reside in the kernel, and thus have deterministic
interrupt and process behaviour, and not use virtual memory. A HD is nice
for logging lots of data.

Anyway, it is much better than DOS. And If I had an ARM embedded contoller,
I would have used it, and run NetBSD on it, since ARM would be much nicer to
my batteries.

Kim0