From owner-freebsd-hackers  Mon Jun 23 04:55:45 1997
Return-Path: <owner-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.5/8.8.5) id EAA29706
          for hackers-outgoing; Mon, 23 Jun 1997 04:55:45 -0700 (PDT)
Received: from time.cdrom.com (root@time.cdrom.com [204.216.27.226])
          by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id EAA29701
          for <hackers@FreeBSD.ORG>; Mon, 23 Jun 1997 04:55:42 -0700 (PDT)
Received: from time.cdrom.com (jkh@localhost.cdrom.com [127.0.0.1]) by time.cdrom.com (8.8.5/8.6.9) with ESMTP id EAA07005; Mon, 23 Jun 1997 04:55:18 -0700 (PDT)
To: Steve Howe <un_x@anchorage.net>
cc: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de>,
        freebsd-hackers <hackers@FreeBSD.ORG>
Subject: Re: direct access 
In-reply-to: Your message of "Mon, 23 Jun 1997 02:36:37 -0800."
             <Pine.BSF.3.95q.970623002024.21409A-100000@aak.anchorage.net> 
Date: Mon, 23 Jun 1997 04:55:17 -0700
Message-ID: <7001.867066917@time.cdrom.com>
From: "Jordan K. Hubbard" <jkh@time.cdrom.com>
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

> i searched through the maillist archives,
> handbook, and faq, and didn't see 
> much on c-programming i/o basics.
> i'm sure it doesn't take an einstein,
> but of course, i'm basing that on my 
> limited knowledge.  i've only been
> programming since 1981, not 1945,

Well, perhaps you just simply need to accumulate a bit more experience
in SEARCHING since I just this moment wandered over to
www.freebsd.org, typed in /dev/io and some likely mailing lists
(hackers, questions) and presto, I found a whole thread on /dev/io
describing what it's for, when you'd use itf and some of the security
implications therefrom.  I even [gasp] found a short usage snippet from
a posting from Sujal Patel on the 19th of April, 1996:

---
After you open /dev/io as read-only, you can then use inb & outb from
machine/cpufunc.h--

#include <stdio.h>
#include <sys/fcntl.h>
#include <machine/cpufunc.h>

main()
{
        open ("/dev/io", O_RDONLY);
        outb (0x3f8, 0xff);
}
---

It took me all of 40 seconds to do this.  C'mon, Steve, you
can do better than this.  You *will* do better than this.


> > colors.  You read the character back from a backup buffer curses
> > maintains inside the program's address space. 
> 
> i can't find any info on this backup buffer in ncurses.
> i tried "apropos buf", "apropos back", ...  i tried the

Uhhhh. But you're clearly driving off the road at this point (and
that should be as obvious to you as anyone) so why would you expect
curses to document its internal data structures in the man page?
Hell, we can barely get programmers to document the published APIs,
much less their data structures.  Go look at the source, dude!
It will explain all! :-)

> what would it give us to explore anything?  maybe unique
> things exist that we all don't know about.

No argument there - explore away!  In fact, if you'd used the time you
spent asking and answering all these questions in just a little more
diligent exploration with a search engine... :)

> i would like to use FreeBSD for embedded systems, and the kernel
> doesn't support devices i need to use.  maybe lkm's -are- what i need?

Well, you could always try it.  Experience is the best teacher, an
even better one than Joerg. :)

					Jordan