From owner-freebsd-questions  Wed Jun 19 11:01:31 1996
Return-Path: owner-questions
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id LAA06327
          for questions-outgoing; Wed, 19 Jun 1996 11:01:31 -0700 (PDT)
Received: from hammurabi.nh.ultra.net (hammurabi.nh.ultra.net [205.162.79.24])
          by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id LAA06322
          for <questions@freebsd.org>; Wed, 19 Jun 1996 11:01:29 -0700 (PDT)
Received: from larry ([192.32.36.129]) by hammurabi.nh.ultra.net (8.7.4/dae0.6) with SMTP id OAA05150 for <questions@freebsd.org>; Wed, 19 Jun 1996 14:01:20 -0400 (EDT)
Message-ID: <31C80975.41C67EA6@qosnet.com>
Date: Wed, 19 Jun 1996 14:06:45 +0000
From: Michael Saal <msaal@qosnet.com>
X-Mailer: Mozilla 3.0b3 (X11; I; FreeBSD 2.1.0-RELEASE i386)
MIME-Version: 1.0
To: questions@freebsd.org
Subject: ?: allocating physical memory for a driver
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: owner-questions@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

I am writing a driver for a bus mastering ISA card.

How do I allocate physical memory and make sure that is located below
the 16M boundry addressable by the ISA bus?

Is malloc("memory size", M_DEVBUF, M_NOWAIT) sufficient? If it is I
don't see how you can make sure the memory is in the right range with
out testing the resulting pointer.

Thanks, Mike Saal