Re: [hatari-devel] New WinUAE core issue with Bad Mood?

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 08/12/2014 17:37, Roger Burrows a écrit :
> As you can see, we assume it's a 68030/68ec030 and try to clear the TTRs/ACRs.
> If that doesn't work, we try the 68040/68060 initialisation.  Otherwise it's a
> 68030/68ec030 and we try to clear the TC.  Whether or not that works, we're
> done 68030/68ec030 PMMU initialisation.
>
> Hope that clears things up,
> Roger

Hi,

I understand better, this matches what I saw while tracing the boot.

Regarding 6ec030, this is what Tony told me regarding TC and his 
experience with 68ec030 on Amiga :

"Enforcer does use full MMU and it can work with some EC030's, at least 
partially. I had one, Enforcer worked, most other programs that use MMU 
simply hung the system immediately.

As I said previously, there are 680EC030's that have partially broken 
MMU, most operations work but some don't. Probably 68030's that got 
relabeled as EC because some MMU-only factory check/test failed."


So, it seems checking TC is not 100% foolproof to ensure you have a 
working MMU. If the cpu was made as a 68030, but failed at some quality 
checks in the factory and was relabeled/sold as a 68ec030, TC register 
will exist, but CPU might give undefined results when really using MMU 
translation's tables.

Well, I'm not sure some 68ec030 were used in some Atari or TT/Falcon 
extension boards, so this is rather theoretical in the end (unless you 
want EmuTOS to run on Amiga :) )


Nicolas