Summary: SCSI Device Drivers

[gaw at mercury.acc.com]

Recently I requested information on writing a device driver for a device
attached off the SCSI bus of SUN systems(any make or model).  I received
the following replies which I am posting to the net for all interested
parties to have access to.  Attached below is my initial mailgram followed
by the responses received.  

[[Ed's Note: Initial mail deleted - see Sunspots v9n399. -bdg]]

Glen A. Warholic 
gaw at mercury.acc.com 
Advanced Computer Communications

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvResponses followvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

X-Subject: Re: SCSI device drivers

> It does reference two documents, "SCSI Implementation Guide" and
> "SCSA:SUN Common SCSI Architecture". Has anyone out there written a
> device driver for a device on the SCSI bus and if so could they tell
> me if these manuals are worth obtaining?  

Yes. they are fairly useful. Even more useful, essential I might say, if
you're trying to write a device driver to interface with the Sun SCSI port
is a product from the Sun Consulting group called the SIP device driver
interface. If you want to use Sun's SCSI chip, your driver is going to
have to co-exist with sd, st, etc. The SIP interface provides you a
consistent framework so that your driver's requests are handled without
stomping on everything else.  I've used it and it's a pretty neat package,
complete with examples and what's more, since the current version is SCSA
compliant, once written, your driver can be easily ported to almost any
Sun box. Your sales person should be able to put you in touch with the
proper Sun Consulting people. Sorry, I don't remember pricing, but if I
remember, it was not outrageous.

> Secondly are there any gotchas that are not documented anywhere?  

I don't think I've even done a driver (or software) where there weren't
some gotchas. It's the kind of thing you deal with as they come up.
Generally I've found Sun SCSI stuff to be pretty solid.

> How compatible is the SUN SCSI bus with that of other vendors, 
> hardware and software wise?

Should be totally compatible.

> Any other information on this topic would be greatly appreciated.

See above. Oh yeah, as you might infer from the signature below, we
provide consulting services on things like SCSI device drivers.

Brad Albom
Software Engineering Solutions, Inc
email : brada at eng.sun.com - Best 

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X-Subject: SCSI device drivers

Someone just posted the address of an anonymous ftp site that has a IBM RT
SCSI device driver.  Maybe you could pick that up and try to port it to a
Sun.  You can find the article in comp.archives.

Dan Guilderson                               ryan at berlin-gw.diag.stratus.com
Stratus Computer, Inc., Marlboro, MA, USA    #include <stddisclaimer.h>