Re: [hatari-devel] 68030 MMU work

[Uwe Seimet <Uwe.Seimet@xxxxxxxxx>]

Hi,
 
> That's an interesting point, indeed. My guess is that when the PMMU
> needs information located in the main memory the Alternate Function Code
> register SFC signals that this is a supervisor mode access. This way the
> PMMU would not be restricted by its own (page table) rules on the one
> hand, on the other hand all PMMU rules would still apply to regular
> programs, i.e. code not executed internally by the CPU.

Additionally, by signaling supervisor mode access in the SFC also
external hardware that checks bus signals would allow the access even
when the CPU is in user mode. The more I think about this, the more sense
it seems to make ;-).
 
Take care

Uwe