Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!nrl-cmf!cmcl2!brl-adm!umd5!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!uiucdcs!meccts!viper!dave
From: dave@viper.Lynx.MN.Org (David Messer)
Newsgroups: comp.unix.microport
Subject: Re: Physical memory
Message-ID: <643@viper.Lynx.MN.Org>
Date: 23 Feb 88 19:28:55 GMT
References: <122@ucrmath.UUCP>
Reply-To: dave@viper.UUCP (David Messer)
Organization: Lynx Data Systems, Eagan, MN
Lines: 33

In article <122@ucrmath.UUCP> jantypas@soft21.UUCP (John Antypas) writes:
 >Anyone know how to get hold of physical memory in a driver?  (I/O 
 >physical memory NOT created by a kernel malloc().)
 >
 >John Antypas -- Soft21 --21st Century Software:
 >
 >UUCP: {garp, killer, pyramid, reed, sdcsvax!ucsd!ucrmath}!soft21!jantypas
 >Internet: jantypas%soft21.UUCP@{eddie.MIT.EDU, ucsd.UCSD.EDU}

Yes, there are four routines included in the libraries to do
this.  They are described in linkkit/doc/link.doc.  Here is
there discription from that file:

	fpbyte  (long physical address)
	fpword  (long physical address)
		Get byte or word at physical address.
		Don't return anything.  If there is no hardware at given 
		address, behavior is unpredictable; garbage is usually returned.  
	spbyte  (long physical address, char data)
	spword  (long physical address, int  data)
		Set byte or word at physical address to data.

It is very important to read link.doc before writing any
kernal code, you will probably not be succesful otherwise.
-- 
If you can't convince |   David Messer - (dave@Lynx.MN.Org)
them, confuse them.   |   Lynx Data Systems
   -- Harry S. Truman |
                      |   amdahl  --!meccts!viper!dave
                      |   rutgers /

Copyright 1987 David Messer -- All Rights Reserved
This work may be freely copied.  Any restrictions on
redistribution of this work are prohibited.