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Subject: Re: Can't put 512MB ram in box ... Extended memory question.
In-Reply-To: <199704230156.LAA18515@genesis.atrad.adelaide.edu.au> from Michael Smith at "Apr 23, 97 11:26:05 am"
To: msmith@atrad.adelaide.edu.au (Michael Smith)
Date: Tue, 22 Apr 1997 18:11:11 -1000 (HST)
Cc: joe@via.net, mrcpu@cdsnet.net, hackers@freebsd.org
From: "David Langford" <langfod@dihelix.com>
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>> Why the need for the MAXMEM config variable?
>> 
>> Why not just probe for maximum memosry size at boot time?
>
>Because there's no standard behaviour when it comes to accessing
>nonexistent memory.  Some systems mirror their memory, ie. with 64M on
>the board, addresses are all modulo-64M.  Others will spontaneously
>reboot if you try to access an address with no memory behind them.
>
>> Joe
>]] Mike Smith, Software Engineer        msmith@gsoft.com.au             [[

Is it my imagination or doesnt BSDI handle this fairly automagically?

Also what are the consequences of setting MAXMEM to a high number
even on low memory machine. 
I thought that I saw the GENERIC kernel et at 128K.

-David Langfod
 langfod@dihelix.com