Re: [hatari-devel] add support for TT ram ?

[Douglas Little <doug694@xxxxxxxxxxxxxx>]

As for having more than 16 MB, I think it can also be handled directly in Hatari in memory.c, because we already do our own translations (for example to map IO regs at $ffffxxxx to $00ffxxxx). These translations are done at the memory_bank level, without requiring an MMU, so it doesn't add any cost since that's the generic mechanism when Hatari wants to translate a logical address in ST space to the physical address in the PC space.

This is probably be best place to do it - but I suspect the 68030 PMMU tree will not permit the CPU to 'see' that mapped memory, without modifying it. It gets first chance at translation, and the default translation is repeat-or-buserr, from $01000000 onwards, and then the whole lot is repeated again, noncacheable (IIRC - may have mixed up a couple of details).

Unless Hatari is getting between the 030 and its PMMU?

Still - it makes more sense for it to work that way, and perhaps use software (AUTO folder) to modify PMMU on the emulation side to make it visible?

I can dig out the TOS 4.04 PMMU memory map later and post it here if it helps any.

D