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Date: Mon, 8 May 1995 16:21:48 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199505080621.QAA05537@godzilla.zeta.org.au>
To: freebsd-hackers@FreeBSD.org, gardners@ist.flinders.edu.au
Subject: Re: how about an IO filesystem
Sender: hackers-owner@FreeBSD.org
Precedence: bulk

>1) Is there a nice interface for FreeBSD that will let me do direct
>chip-bashing to selected CPU io ports.. ie, i say to the system 'i want to
>have direct access to ports 0x378,0x379' and if the ports are not in use,
>then the system blocks all other processes from activities which would effect
>these ports, and releases port protection on those addresses.

There are only device drivers and direct unprotected access (i.e. security
holes) for things like the X server.

>If there isnt a way, how about the following:

>a 1 KB /dev/ports or similar file , which maps to the 1KB of ISA port space.
>It is generically read-write, except for ports in use etc.. If a process would
>like exclusive use of a port it uses normal file locking methods to lock the
>region of the file it wants.

Locking stuff isn't quite right even for devices drivers.

Bruce