*BSD News Article 55137


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From: gillham@andrews.edu (Andrew Gillham)
Newsgroups: comp.unix.bsd.netbsd.misc
Subject: Re: sd0: DMA beyond ISA whazzat?
Date: 22 Nov 1995 01:34:31 GMT
Organization: Andrews University
Lines: 24
Message-ID: <48tun7$674@orion.cc.andrews.edu>
References: <48snme$1p1g@info4.rus.uni-stuttgart.de>
NNTP-Posting-Host: edmund.cs.andrews.edu

In article <48snme$1p1g@info4.rus.uni-stuttgart.de> schweikh@zeiss.ito.uni-stuttgart.de (Jens Schweikhardt) writes:
>Hello,
>
>(zillions of these lines, in fact). Is there anything
>I can do - apart from removing 4MB of the 20MB RAM I have -
>to make "DMA beyond ISA" work? I've looked at the FAQ
>but could not find something addressing this.
>Have I been blind?

You could take out _more_ than 4MB... :-) :-)

Seriously though, NetBSD/i386 doesn't have bounce buffer support yet, so
running with 16MB is about the only option.  You can configure the
kernel to only see 16MB, you don't need to actually remove the RAM.
(except when you compile your special kernel that is)
Look in /sys/arch/i386/i386/machdep.c for 'RTC' and change the
'biosextmem = xxxxxxxx' to 'biosextmem = 15 * 1024;'

-Andrew
-- 
============================ Real 32bit multi-tasking UN*X System
Andrew Gillham             | TCP/IP,NFS,PPP,4.4BSD-lite,multi-user
gillham@andrews.edu        | i386,sparc,alpha,mac68k,amiga,others
LAN/WAN/NW/UN*X specialist |   ---> http://www.NetBSD.org <---