Re: [MiNT] mint & mmu

["Konrad Kokoszkiewicz" <draco@obta.uw.edu.pl>]

> Any opinions why it shouldn't work? ;-)

You seem forgetting about 68k privileged instructions, i.e. ones which only
work in supermode. Obviously, programs do not usually siwtch to supermode to
use them, but since they are in supermode, there is no guarantee that
privileged instrctions would not be in use.

So you also have to emulate them (as TOS 4.04 emulates "move from SR" in
user mode).

And also, everything you mentioned as needs for supermode is perfectly
possible without using the Super() call. Obviously, under MiNT, not under
TOS.

The only way I can think of, which would save the Super() call and made it
safe, is somehow emulate all the code, or some other way catch every
instruction, that is executed between two Super() calls or inside Supexec(),
and heavily check that these instructions do "legal" things, and kill the
program otherwise.

This way old programs which switch to Super() to read just cookie jar ptr,
would still operate, and Super() itself would become both safe for the
system and useless for new programs.

I am sure that demo coders will love this idea :>

--
CVV
Konrad M.Kokoszkiewicz, http://draco.atari.org

** Ea natura multitudinis est,
** aut seruit humiliter, aut superbe dominatur.
** Taka to juz natura pospólstwa, albo sluzalczo sie plaszczy,
** albo bezczelnie sie panoszy. (Liwiusz XXIV, 25).