Re: New beta kernel

[Sven Karlsson <sven@it.lth.se>]

> > > There is another small patch, which could be added to the next Kernel-release:
> > > this patch is neccessary to run mint on a 68060-processor.
> > 
> > any other 040 or 060 related patches? Or perhaps a MiNT060 with memory
> > protection?
> 
> MiNT memory protection doesn't run on 040? As far as I remember, the file
> memprot.c is 040-aware, but makefile compiles it with -m68030 (ALWAYS).
> What does happen, if you compile the whole kernel AND memprot.c with
> -m68040?

The MMU handling routs are not 040/060 compatible. It is possible to
write them so that they work on all MMUable cpus since the 040 MMU
is a subset of the 030 MMU which in turn is a subset of the MMU
coprocessor. The 060 MMU is identical to the 040 MMU.

The restrictions are (AFAIK)

1. the MMU tree needs to be organized in a certain way:
   (this is the only organisation the 040/060 MMU handles)

                       top_level (7bits)
                               |
                   +---....................---+
                   |                          |
                 2nd level (7bits)
                   |
           +---........--+
           |
        3rd level(6 or 5bits)
           |
     +--......--+
     |
   descriptors

2. The pagesize can only be 4k or 8k (I think 8k would be better since it would
   use less entries in the ATCs)

3. The types of descriptors are limited.


Regards
 Sven