Re: [hatari-devel] Data cache Issues?

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On maanantai 29 kesäkuu 2015, Nicolas Pomarède wrote:
> Regarding chainz and jewelz, the problem was related to the blitter :
> during the init, the game moves some blocks of data using the blitter
> (can't say what kind of data it is) and it reads data near the end of
> the RAM to copy it elsewhere.
> The problem is that the code seems buggy, because it starts to read in
> the RAM, then it reads beyond the RAM in the region that should give a
> bus error :(
> So, with 4 MB RAM, it will read $400000,$400002, ...

They need 14MB.


> There was an error in the blitter code because it triggered a bus error
> in that case ; but as the blitter uses DMA, it should not do bus error,
> it should ignore the write or return random data when reading.
> 
> This is now fixed,so chainz and jewelz don't bomb at start.
> 
> Nevertheless, they now stop on the same loop as tautology, waiting for
> bit 0 of ffa202 to change.

Confirmed, they don't bomb anymore, but freeze like T2.


> I confirm this work with old cpu core, so I
> think that something was broken when I updated the code to integrate DSP
> interrupt into recent WinUAE core (which uses a slightly different code
> path)

Would it help if I try to bisect it?


> I will have a look, having a working case will help fixing this.

I noticed you had added one DSP specific fix, but these 3 still freeze.


> Didn't have a look to the other cases for now.

IMHO Corsair is most interesting of the rest because data cache is
what breaks it.

If needed, I can send you my version.


	- Eero