RE: MMU questions?

[stehlik@cas3.zlin.vutbr.cz (Petr Stehlik)]

On Wed, 3 Jun 1998 11:20:12 +0200 , Sven Karlsson wrote:

SK>	1. A program cause a  page fault and the virtual memory manager
SK>starts
SK>	   working.
SK>	2. When the VMM is working an interrupt occurs.
SK>	3. The interrupt cause a page fault.

let me note just two little things:

1) MiNT, for some unknown reason, loads all daemons into ST-RAM
automagically, regardless of their FastRAM flags. Perhaps this was the
first step to ensure that there would be no interrupt driven programs in
virtual/alternate memory

2) even if the MiNT implementation of virtual RAM would crash with
interrupt driven programs running in it, we could always easily ensure
that such a program is loaded into ST-RAM - simply by setting its
FastRAM flags.

Besides, there's a kind of virtual memory support for 68030 in MiNT.
What would we need is a better 040+ support. With the current prices of
SIMM/DIMM I don't think we need real virtual memory that badly - proper
paging to eliminate memory fragmentation and perhaps real memory
protection would be much more useful.

There are people that do understand programming of 68040 or 68060.
Unfortunately those people are not very familiar with internals of MiNT.
All we need is to find somebody that understands MiNT's memory
protection and would be able to explain it to 68040+ programmer :-) Then
the 68040+ man would design a new 040+ friendly method of that
algorithm that would have to be implemented back into the MiNT kernel.

Petr
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