From owner-freebsd-hackers  Tue Jun 24 16:53:56 1997
Return-Path: <owner-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.5/8.8.5) id QAA14483
          for hackers-outgoing; Tue, 24 Jun 1997 16:53:56 -0700 (PDT)
Received: from argus.nuke.net (pm3-p18.tfs.net [206.154.183.210])
          by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id QAA14413
          for <freebsd-hackers@freebsd.org>; Tue, 24 Jun 1997 16:53:21 -0700 (PDT)
Received: (from jbryant@localhost)
	by argus.nuke.net (8.8.5/8.8.5) id SAA04082;
	Tue, 24 Jun 1997 18:52:06 -0500 (CDT)
From: Jim Bryant <jbryant@argus.nuke.net>
Message-Id: <199706242352.SAA04082@argus.nuke.net>
Subject: Re: BSD io
In-Reply-To: <Pine.BSF.3.95q.970623222529.7612B-100000@aak.anchorage.net> from Steve Howe at "Jun 23, 97 10:41:44 pm"
To: un_x@anchorage.net (Steve Howe)
Date: Tue, 24 Jun 1997 18:52:05 -0500 (CDT)
Cc: freebsd-hackers@freebsd.org
Reply-to: jbryant@tfs.net
X-Windows: R00LZ!@#  MS-Winbl0wz DR00LZ!@#
X-Mailer: ELM [version 2.4ME+ PL31H (25)]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: owner-hackers@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

In reply:
> > > i see a few generalizations about device drivers,
> > > but no solid instructions / rules for FreeBSD.
> 
> > in /usr/share/examples/drivers 
> > are two shell scripts that WRITE A DRIVER FOR YOU
> 
> my directory is empty, what dist fills the drivers directory?

mine too...

> > > > learn about what's going on, attach a debugger to the kernel and
> > > > look at both the source _and_ the data.
> 
> > with 2 machines hooked together with a serial cable
> > and the right s/w loaded,
> > you can single step the 2md machine in the kernel
> > and examine each line of C as it's run, and look at all variables,
> > structures etc.
> > THAT is educational, as it takes into account all the mappings for you.
> 
> why isn't there a tutorial on the kmem/gdb methods
> to help people out that want to learn more?
> things should take matters of days, not weeks.
> tutorials delayed, is learning denied.

the source code is there... i suggest getting the 4.4BSD "design of"
book, and manuals...  Good starting points.

jim
-- 
All opinions expressed are mine, if you   | "I will not be pushed, stamped,
think otherwise, then go jump into turbid | briefed, debriefed, indexed, or
radioactive waters and yell WAHOO !!!     | numbered!" - #1, "The Prisoner"
 jbryant@tfs.net - KC5VDJ 2M, 70cm, KPC-3+ - kc5vdj@wv0t.#neks.ks.usa.noam