[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [MiNT] 040/060 MMU tree builder



 Hi!

On Wed, 19 May 1999, Thomas Binder wrote:

> Hi!
> 
> On Tue, May 18, 1999 at 01:52:38AM +0200, Michael Schwingen wrote:
> > Correct. You can init and enable the MMU with a 1:1 mapping from the auto
> > folder - however, it is too late then to remap RAM, since GEMDOS is already
> > initialized.
> 
> How does the "infamous" Splitram.prg for the Hades work, as it actually
> does remap RAM, i.e. split the large ST-RAM block into ST-RAM and
> TT-RAM, as it should be?

 No, it does not remap any addresses. All it does is copy phystop.w to
memtop and _memtop. Then it put $0x00E00000 in phystop.w. And then jumps
trough the reset handler to make a warm boot. This means that the two
megabytes of ram located between $0x00E0000 and $0x01000000 is lost. A
couple of days ago I made a couple of attempts to remap some of the TT ram
to use that area, but without success. I will make another attempt soon,
but now I'm trying to find the time to complete the set_mmu.prg itself.


 So, the question now is.. why does the lates MiNT fail big-time when
phystop.w contains a very high address and memtop, _memtop is cleared?






 Odd Skancke - ozk@atari.org