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To: Tony Overfield <tony@dell.com>
cc: John-Mark Gurney <gurney_j@resnet.uoregon.edu>,
        Chuck Robey <chuckr@glue.umd.edu>, Mike Smith <mike@smith.net.au>,
        Terry Lambert <tlambert@primenet.com>, jamil@trojanhorse.ml.org,
        hackers@freebsd.org, Jonathan Mini <j_mini@efn.org>
Subject: Re: >64MB 
In-reply-to: Your message of "Thu, 06 Nov 1997 15:04:48 MDT."
             <3.0.3.32.19971106150448.006d5438@bugs.us.dell.com> 
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Date: Fri, 07 Nov 1997 12:34:59 +1030
From: Mike Smith <mike@smith.net.au>
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> My ambiguous question reworded would say...
> 
> Once you are in the kernel startup code and running in protected mode, 
> why not simply switch back to real mode for BIOS calls and etc. instead 
> of trying to set up a VM86() facility?  I think it's easier and much 
> better for compatibility while booting.

The kernel is loaded above 1M, so you would have to be careful to make 
sure that your BIOS calls came out of the lowest 64K.  That could be 
done with a dispatcher in locore.s though.

The other reason is that I don't know how to make the change.  8)  If I 
did, I'd certainly consider it, although vm86 has a few other uses that 
argue for using it just out of commonality.

mike