Re: [hatari-devel] MMU compatibility (was: Tests of Falcon games)

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 10/17/20 10:24 AM, laurent.sallafranque@xxxxxxx wrote:
> Thanks Eero.
> I think maybe that mmu enabled should now be the normal setting for Falcon
> emulation and one should disable MMU only for speed or special case.

Although better, I think MMU emulation in Hatari
is still too buggy to be enabled by default, at
least in regards to prefetch & cache emulation
(--compatible on --cpu-exact on).

Note: based on what Toni has said about things
working on Amiga side with WinUAE, this seems to
be Hatari or Atari specific problem.  Do we have
some HW components which memory accesses don't
go through MMU/cache emulation like it should
(DSP, blitter, DMA etc)?


> As I said before, the falcon CPU has à MMU natively and I also believe that with
> the latest devs, it works better now.


	- Eero

> Le 17 oct. 2020 01:38, Eero Tamminen <oak@xxxxxxxxxxxxxx> a écrit :
>
>      Hi,
>
>      On 10/4/20 7:59 PM, Eero Tamminen wrote:
>       > On 10/4/20 3:38 PM, Laurent Sallafranque wrote:
>      [...]
>       >> capy : not tested
>       >
>       > Dies now to:
>       > WARN : Bus Error reading at address $ff9c00, PC=$3dfe2 addr_e3=3dfe2
>       > op_e3=4cd8
>       >
>       > This is *regression* from Hatari v2.2.1.
>       >
>       > (FF9C00 is just after normal VIDEL regs.)
>
>      Works if MMU is enabled.  Doesn't require MMU
>      with Hatari v2.2.1.
>
>
>       >> chainz : not tested
>       >
>       > Works fine.  If MMU is enabled, there's some
>       > problem at start, but game can still be started.
>       >
>       >
>       >> Color runner : no evolution
>
>      It requires now MMU to reach the point where it got with earlier Hatari
>      versions without MMU.
>
>
>       >> Sokoban by FUN : game freeze (black screen) after Bus Error writing at
>       >> address $ff97fe, PC=$e12bce addr_e3=e12bce op_e3=4ad5
>       >
>       > same.
>
>      Works with MMU.
>
>      => I'm starting to wonder whether a lot of
>           the other games that earlier worked when
>           MMU was disabled, work now only when it's
>           enabled
>
>
>      I've tested few games more and updated the Falcon
>      games info to compatibility list.
>
>      I'll look at Laurent's demo compatibility notes
>      next week.
>
>
>      - Eero