Re: Linux, UDI and SCO.

David Hollister (dhollist@Iphase.COM)
Tue, 22 Sep 1998 07:38:13 -0600 (CST)


Gerard Roudier says:
>
> I have had a look into UDI books. This looks to me as the result on N
> years of brain masturbation from 'has been' people that enjoy turning
> simple things into complex ones since this makes feel them intelligent.
> Let me doubt that a driver blindly written using these specs will work
> without change on any architecture and be optimal enough not to be
> ridiculous. All the UDI kernel interface reinvention will make debugging
> a pain. What about the overhead in code lines and CPU cycles due UDI
> stuff ?

The reason it's so complex is because all the *nix implementations are so
different. It's quite an undertaking to attempt to create a standard interface
among such varying implmentations.

UDI prototype environments (without kernel modifications, of course) already
exist for Solaris and HP-UX. I don't know about performance numbers but as
I've said before, our own UDI-ish driver interface which is designed along
somewhat the same lines as UDI has shown no real noticable performance
difference for our HP-UX implementation (I'm not sure of Solaris performance
numbers). I also have a Linux implementation which has also shown very
similar performance to a native Linux driver I also wrote for one of our FDDI
devices.

> I am not against UDI. In fact I don't care of such proposal. I want an
> O/S that fits my needs, and for now I have one that did'nt need UDI in
> order to be so.

UDI isn't geared toward users. It's geared toward driver developers. Once
an OS environment is in place, you don't need to worry about it. You write
a new driver to drive some piece of hardware with the knowledge that all of
the OS dependencies have already been taken care of. It's a tool for more
rapid, standardized driver development. Whether the drivers your OS uses
are written to UDI or not has no bearing on your use of that OS.

-- 
David Hollister           Interphase Corporation      dhollist@iphase.com
Software Engineer         Dallas, TX
                      http://www.public.asu.edu/~dhollist

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