*BSD News Article 15952


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Newsgroups: comp.os.386bsd.development
Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!haven.umd.edu!uunet!pipex!uknet!mcsun!sun4nl!relay.philips.nl!cnplss5!rooij
From: rooij@mozart.cft.philips.nl (Guido van Rooij)
Subject: Re: kernel hacking tips
Message-ID: <1993May12.102918.10890@cnplss5.cnps.philips.nl>
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References: <PC123.93May11105430@bootes.cus.cam.ac.uk> <1so4eaINNibt@fstgds01.tu-graz.ac.at> <1993May11.192459.1618@ucsu.Colorado.EDU>
Date: Wed, 12 May 1993 10:29:18 GMT
Lines: 21

galbrait@rintintin.Colorado.EDU (GALBRAITH JOHN) writes:

>Has anybody tried to cheat and write a driver that does nothing but give
>you access to an outb() and inb() instruction?  This might speed development
>for a big project.  The new driver gets written and debugged before it is ever
>added to the kernel so you don't have to constantly reboot.  Or what about
>doing an inline assembly call to outb with no kernel support at all?

I posted a patch some time ago that fixed incorrect behaviour regarding inb()
and outb() (anyone could execute these instaructions, resulting in
a failure only half of the time!!.

I also adapted the kernel a bit so that opening /dev/mem gives you
permission to execute inb's and outb's.
It was said that the kernel already had this functionality but that
ism *not* true.

>john 
>galbrait@rintintin.colorado.edu

-Guido