Re: [MiNT] memory protection on Afterburner040

[joska@nuts.edu (Jo Even Skarstein)]

On Sat, 1 May 1999 23:45:14 +0200, Thomas Binder wrote:

> impossible. Unfortunately, this currently also means that the complete
> kernel code is unprotected, too!
> 
> A solution for the latter would be to write a tool that loads MiNT to an
> 8K-aligned address, relocates and runs it (with some special parameter
> to tell it it should protect its code). Any volunteers?

A less complicated method would be to write-protect the TEXT-segment of
the kernel. It's not nearly as effective as real write-protection, but
a lot better than nothing.

> After MiNT with active memory protection is run, each process gets its
> own MMU table, so I don't think enabling the cb-cache will work, then,
> as it for sure won't alter all MMU tables (remember, the type of caching
> is either set via the MMU or the transparent translation registers,
> where the latter are checked by MiNT to not cover the memory it wants to
> protect).

I just checked, and copyback is *not* enabled when memory-protection is
active :-/ Unfortunately it's not possible to activate CB until after N.AES
has changed resolution, because Nova-VDI crashes when changing rez. and CB
is enabled... Hmmm, perhaps if I move the Nova-stuff to ST-RAM... Nope, it
didn't work.

This is a really PITA, because my system is usually *very* stable with CB
enabled. Would it be possible to let MiNT set the cache-mode "on the fly" on
all pages?

Btw. I've discovered one rather annoying side-effect of MP on my Afterburner:
I can't reset anymore! Reset-button, keyboard, shutdown... Nothing works, I
have to switch my Falcon off and on again.


/*
** Jo Even Skarstein    http://www.stud.ntnu.no/~josk/
**
**    beer - maria mckee - atari falcon - babylon 5
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