Re: Virtual Memory (Was Re: Kernel 1.14.7 available)

[Konrad Kokoszkiewicz <draco@mi.com.pl>]

> I don't know how far your new VM is from ready, but if your aim is to change it
> completly I think I can help you, as I did a patch some years ago to let my MiNT
> kernel use virtual memory. It works on my Falcon and has some interesting 
> features (IMO):
> 1 It uses original data that was already in the MiNT kernel for tha VM (Yes,
>   some of the MiNT memory handling routs were VM aware !
>   e.g. Look for init_swap in mem.c)
>   So it looks and works better (In My Own Humble Opinion) than the current VM,
>   (the VM is not handled by the kernel as TT-RAM but as an other kind of RAM
>    everywhere it was possible so that you won't have VM when you would like to
>    get the faster TT-Ram). 
> 
> 2 It can do memory paging even if virtual memory is disabled so no more fragmen
>   tation.
> 
> 3 Memory protection still works even if virtual memory is enabled.

That's rather a good new :-) If that works, I wonder if you'd be able to
apply all necessary changes to the current 1.15 source, then send diffs
back. I'll send you the current tree if you like.

> P.S.
> I think my patch should work ok on a TT, as this one as no Blitter,
> unfortunately I have no TT and although I have relative diffs of my VM routs
> I'm not sure these diffs will apply ok on a kernel more recent than my old one.
> 
> P.P.S
> If somebody had a better idea to solve my problem it could help me.

The only solution I can think is that the blitter should get permanently
disabled if a sort of VRAM is active. That may be done by hooking a patch
to trap #14 on Falcons, that would always disable the chip and return "no
blitter" if inquired.

--
Konrad M.Kokoszkiewicz
|mail: draco@mi.com.pl                  | Atari Falcon030/TT030/65XE |
|http://www.orient.uw.edu.pl/~conradus/ | ** FreeMiNT development ** |

** Ea natura multitudinis est,
** aut servit humiliter, aut superbe dominatur (Liv. XXIV,25)
*************************************************************
** U pospolstwa normalne jest, ze albo sluzy ono unizenie,
** albo bezczelnie sie panoszy.