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From: stevea@mcdclv.UUCP (Steve Alexander)
Newsgroups: comp.sys.m68k
Subject: Re: How to access local I/O devices from a user process in SysV/68?
Message-ID: <637@mcdclv.UUCP>
Date: 4 Dec 90 16:08:19 GMT
References: <1990Dec3.040634.1428@cs.UAlberta.CA>
Reply-To: stevea@mcdclv.UUCP (Steve Alexander)
Organization: Motorola MCD, Cleveland
Lines: 21

In article <1990Dec3.040634.1428@cs.UAlberta.CA> rasit@cs.UAlberta.CA (M. Rasit Eskicioglu) writes:
>Dear netters,
>
>I want to write code that would access to Local I/O Devices directly. For
>example, I want to read LANCE registers. As they are not mapped into the
>user's space in SysV/68V3R6, I always get memory protection error (signal 11).

Look at shmget(2), shmctl(2), and shmop(2) in the Programmers
Reference manual (note the IPC_PHYS parameter).  Physical shared
memory MUST be allocated on 4KB memory page boundaries under sysV/68.
Also see the chapter on Interprocess Communication Techniques (IPC) in
the Programmers Guide manual for examples.

Stevea


-- 
Steve Alexander            | a twelve ton cast iron soda cracker,
Motorola Cleveland         | the stress on an aluminum plastic injection mold,
                           | silly snowflakes dancing wildly for no one,
                           | scotch tape, sticky on NO sides.            [sja]