From mboxrd@z Thu Jan  1 00:00:00 1970
From: ron minnich <rminnich@lanl.gov>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] pathetic
In-Reply-To: <20040226011539.N7383@edinburgh.cisco.com>
Message-ID: <Pine.LNX.4.44.0402252044120.13951-100000@maxroach.lanl.gov>
MIME-Version: 1.0
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Date: Wed, 25 Feb 2004 20:45:19 -0700
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On Thu, 26 Feb 2004, Derek Fawcus wrote:

> Well the descriptors have to be there,  but they're ususally set for 1:1
> mapping (phys == linear).  It used to be that linux used the segments
> for proc protection,  then just for the 3G limit,  now I believe they
> are set 1:1 and everything done with pages.

yes.

> err - later.
>   Virt => Linear (via paging h/w).  Then Linear => Phys (via segment h/w).

geez did I get this backward again. In my pentium manual it shows it going
the other way.


> That's what AMD are supposed to have added.  That's what the whole
> hoohaw is about, they've added a bit somewhere (I'd guess a spare bit
> from the page descriptor) such that a page can be non execute.

wow, I'm so excited. Oh, wait, I'm not. Oh well. :-)

ron