From owner-freebsd-questions Tue Aug 8 15:40:59 1995 Return-Path: questions-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.11/8.6.6) id PAA18941 for questions-outgoing; Tue, 8 Aug 1995 15:40:59 -0700 Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.cdrom.com (8.6.11/8.6.6) with ESMTP id PAA18927 for ; Tue, 8 Aug 1995 15:40:55 -0700 Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.9/8.6.9) id IAA26591; Wed, 9 Aug 1995 08:37:22 +0930 From: Michael Smith Message-Id: <199508082307.IAA26591@genesis.atrad.adelaide.edu.au> Subject: Re: Accessing i/o map space with freebsd 2.1.0 To: erich@lodgenet.com (Eric L. Hernes) Date: Wed, 9 Aug 1995 08:37:21 +0930 (CST) Cc: msmith@atrad.adelaide.edu.au, ROBIN@ptnsct.nis.za, questions@freebsd.org In-Reply-To: <199508081516.KAA24583@jake.lodgenet.com> from "Eric L. Hernes" at Aug 8, 95 10:16:32 am Content-Type: text Content-Length: 923 Sender: questions-owner@freebsd.org Precedence: bulk Eric L. Hernes stands accused of saying: > > Your program must be run as root; before performing any I/O operations, > > open the file /dev/io. This action grants the process priveledges to > > read and write directly to the hardware. > > > Does this really work? Yes. > in /usr/src/sys/i386/i386/mem.c, it looks like it is #ifdef'ed out. No, that's the old /dev/ioport, which provided an interface with file semantics. /dev/io just sets the IOPL (?) bit for the process, allowing it to do raw IO. Have you actually tried it? > eric. -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] My car has "demand start" - Terry Lambert [[