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From: dailey@frith.uucp (Chris Dailey)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Help --> How to prevent the visit from the dreaded guru
Keywords: Exec, Messages, Protected memory, MMU, Hunks, Caffeine.
Message-ID: <1991Jan7.135627.29673@msuinfo.cl.msu.edu>
Date: 7 Jan 91 13:56:27 GMT
References: <611@caslon.cs.arizona.edu> <1991Jan4.224833.24914@ncsuvx.ncsu.edu> <17130@cbmvax.commodore.com> <1991Jan5.213642.16547@isis.cs.du.edu> <17135@cbmvax.commodore.com>
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In article <17135@cbmvax.commodore.com> jesup@cbmvax.commodore.com (Randell Jesup) writes:
>>  Agreed, adding protection might break large quantities of stuff. How
>>about some kind of retrofit? Create a new object file hunk, say HUNK_FLAGS,
>>which tells you intimate info about the program that LoadSeg is bringing in.
>>You could have a flag to signify "I'm a nice program and I work well under
>>memory protection, so protect me if you can". This would also be an
>>excellent place to finally settle the PURE code problem. Make a hunk flag
>>that signifies, regardless of what the FS bit says, "This code is pure,
>>damnit." ;)
>
>	A better idea.  You _could_ allow segments of code from a loadfile
>to be protected (at least without many problems), and you could allow 
>applications to request protected memory.

I think that would make people very happy.  Would it be possible to
keep that program from writing to unprotected areas of memory except
when dealing with the system structures?  Perhaps give system calls
universal access to all memory but not the user's code?

I consider myself a good programmer (maybe foolishly so  :), and I'm
not hit by the SEG_FAULT that often when I program for school; when I
do get them, I'm thankful my errors are handled as they are.  When I
start programming seriously for the Amiga (ie when I get a 3000) I
might not think this a major problem.  (ie a 15 second boot time might
not be so bad after a GURU-- now I have about 1.5 minutes, plus getting
things back to the state I had them in...)

>Randell Jesup, Keeper of AmigaDos, Commodore Engineering.  
>{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com  BIX: rjesup 
>The compiler runs 
>Like a swift-flowing river 
>I wait in silence.  (From "The Zen of Programming")  ;-)

--
Chris Dailey   dailey@(frith.egr|cpsin.cps).msu.edu
BRD += DDR;           __  __  ___
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num_countries --;  \__/\__/\__/ Snake in the Grass