Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!fernwood!dumbcat!marc
From: marc@dumbcat.sf.ca.us (Marco S Hyman)
Newsgroups: comp.unix.sysv386
Subject: Re: memory mapping (was: '386 Unix Wars)
Summary: See /etc/default/boot
Keywords: sco unix interactive wars
Message-ID: <263@dumbcat.sf.ca.us>
Date: 28 Dec 90 00:09:26 GMT
References: <2812@cirrusl.UUCP> <350@metran.UUCP> <2732@sixhub.UUCP>
Organization: MH Software, Hayward, CA.
Lines: 25

In article <2732@sixhub.UUCP> davidsen@sixhub.UUCP (bill davidsen) writes:
    
      Let me ask a question here, based on something I partially remember
    from setting up ISC some months ago... There was a table which defined
    memory, and we used it to define memory which could not do DMA, to force
    the o/s to fake it. I *thought* I read in the description of that table
    that it could also be used to block out a section of RAM to keep the o/s
    from using it, but to still use RAM *above* the reserved space.

There is a MEMRANGE entry in /etc/default boot.  Mine looks like (386/ix
2.0.2)

	MEMRANGE=0-640K:0,1M-15M:0,16M-15M:1

Note that the last entry (16M-15M:1) is in reverse order.  This tells the OS
to scan from the top down when looking for memory in this range.  The :1
says DON'T use DMA for this range.

I forget where it's documented, maybe someone else can say where in TFM to
look.

// marc
-- 
// marc@dumbcat.sf.ca.us
// {ames,decwrl,sun}!pacbell!dumbcat!marc