Path: utzoo!attcan!uunet!mcsun!hp4nl!philapd!ssp11!dolf
From: dolf@idca.tds.PHILIPS.nl (Dolf Grunbauer)
Newsgroups: comp.sys.m68k
Subject: Re: mc68040 I/D coherency
Message-ID: <765@ssp11.idca.tds.philips.nl>
Date: 1 Jun 90 14:02:34 GMT
References: <41463@brunix.UUCP> <12055@cbmvax.commodore.com>
Organization: Philips Information Systems, Apeldoorn, The Netherlands
Lines: 18

In article <12055@cbmvax.commodore.com> valentin@cbmvax (Valentin Pepelea) writes:
<'They' chose not to support this practice at all. Writing self modifying
<code (Ahem - self distructing code) is not just difficult, it's darn well
<impossible on most systems.
I agree that writing self modifying code should be very hard to be made.

<Geez, I can't believe I am telling you how to write bad code! Hopefully I
<missed some subtle quirk of the '040 which would make this practice impossible
<under any circumstances.
No you don't want it to make it impossible under *any* circumstances. How
about your favorite run-time debugger like 'sdb' or 'adb' or whatever debugger
you are using ? If you put a breakpoint somewhere in the code, the instruction
is replaced by a special trap or someting alike. This is self modifying code.
-- 
Dolf Grunbauer      Tel: +31 55 433233 Internet dolf@idca.tds.philips.nl
Philips Information Systems            UUCP     ...!mcsun!philapd!dolf
Dept. BS Software,  P.O. Box 245, 7300 AE Apeldoorn, The Netherlands 
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