On Tue, 11 May 1999, Jim Dennis wrote:
> > Is there a bare bones "OS" (freeware with source) that starts
> > up an x386, enables 32bit mode, and does some basic round
> > robin scheduling? (the term "OS" is very loose here)
[snip]
> I think there's also a uCOS (microcontroller OS) at
> Cygnus (http://www.cygnus.com) which may be under the
> GPL (most Cygnus work is). I might be mis-remember the
> name on that one, so you'll have to hunt around a bit.
eCos -- embedded Cygnus Operating System
http://sourceware.cygnus.com/ecos/
Its distributed under their own license that is more "friendly" to
commercial shops interested not interested in distributing their source.
It actually is a pretty good compromise. (Note: I'm not a lawyer) It
basically says that if you make any changes to the source code of eCos as
distributed by Cygnus, you must make your changes freely available. But
you are free to write, from scratch/published APIs, any kernel driver you
wish and distribute it any way you wish, even with the rest of eCos, to
your customer. So it makes people play fair with the "community's
investment", but can also do what you like with code you wrote all by
yourself. It is a tempering of the viral quality of the GPL.
eCos is nice because of its extreme modularity (so I'm told; I've not used
it). You can build in only those subsystems you need.
> These are probably the simplest models matching
> your description.
I wonder if something like OSkit
(http://www.cs.utah.edu/projects/flux/oskit/boot-floppy/) might be
simpler. (Again, I've not used it other than playing with the demo disk.)
It is all the low-level x86 code for an OS, without any of the high-level
policy. It's designed for OS research.
The simplest high-level policy is the following code:
#include <stdio.h>
void main()
{
printf("Hello, World\n");
}
--Jeremy
Jeremy Impson
Network Engineer
Advanced Technologies Department
Lockheed Martin Federal Systems
email: [EMAIL PROTECTED]
phone: 607-751-5618
fax: 607-751-6025
