From owner-freebsd-hackers Thu Jan 18 15:17:50 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id PAA11157 for hackers-outgoing; Thu, 18 Jan 1996 15:17:50 -0800 (PST) Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id PAA11114 for ; Thu, 18 Jan 1996 15:17:41 -0800 (PST) Received: from sax.sax.de by irz301.inf.tu-dresden.de (8.6.12/8.6.12-s1) with ESMTP id AAA24757; Fri, 19 Jan 1996 00:17:27 +0100 Received: by sax.sax.de (8.6.11/8.6.12-s1) with UUCP id AAA01742; Fri, 19 Jan 1996 00:17:27 +0100 Received: (from j@localhost) by uriah.heep.sax.de (8.7.3/8.6.9) id XAA29440; Thu, 18 Jan 1996 23:57:41 +0100 (MET) From: J Wunsch Message-Id: <199601182257.XAA29440@uriah.heep.sax.de> Subject: Re: Above286 board To: dutchman@spase.nl (Kees Jan Koster) Date: Thu, 18 Jan 1996 23:57:40 +0100 (MET) Cc: freebsd-hackers@FreeBSD.ORG Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: <199601181416.OAA01326@phobos.spase.nl> from "Kees Jan Koster" at Jan 18, 96 02:16:06 pm X-Phone: +49-351-2012 669 X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-hackers@FreeBSD.ORG Precedence: bulk As Kees Jan Koster wrote: [EMM board] > I'd like to use it as a ram disk for FreeBSD, to have 2MB of fast swap > space. But for that I'll have to write a device driver. > > 1) Has anyone heard of this board? Does anyone use it? Is there > source of a device driver for it? (Any system) EMM should be fairly well documented. It's being addressed in segments, where the active segment is being mapped at some address in the ``ISA hole''. > 2) Can a non-kernel process address the ISA memory space? To > experiment I'd like to be able to write to it's addresses without > rebuilding the kernel. It could, via /dev/[k]mem. An alternative is writing a kernel driver, and hooking it into the kernel as an lkm. See /usr/share/examples/lkm. > The docs tell me that the board can be used to supply _conventional_ > memory via a setup program. That's odd. I didn't think an XT could > address memory via the ISA bus? Or can it? It can, in the ISA hole (0xa0000 ... 0xfffff), though fairly slow. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)