68K hybrid emulation


foft

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Hello! Its a long time since I've been on the Pandora forums! Back in the day I ported the atari800 emulator and gemrb and stuff.

Anyway I'm now mostly playing with FPGAs. I recently tried to add Amiga hybrid emulation to the MiSTer. This is when we use the FPGA for the main system hardware then use the ARM cpu for the processor.
Lets actually try Hybrid Emulation

I have it working with Musashi. This is cool though its actually slightly slower than the FPGA based CPU. So I'd like to make it faster. So I thought, where do all the arm emulation optimisation experts live... Pandora/Pyra forums!

What are the best 68k engines to use for 68000, 68020 and 68040+fpu+mmu emulation? Could be a different one for each case.
I dug out a few, but some of them seem fiddly to get running: Re: Lets actually try Hybrid Emulation
i.e. musashi and cyclone have GREAT docs. The others... not so much.

Many thanks!
 

foft

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Well I have the hardware side done. That is in vhdl and verilog.

So now can mmap the Amiga hardware registers and chip memory from Linux. So looking for a 680x0 jit that I can use standalone. Give it some memory space or access functions and tell it to run.
Post automatically merged:

It’s a dual cortex a9 cpu at 800MHz where I need to run the cpu emulation.
 

levi

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Oh so you're using the FPGA to simulate all of the Paula chips and the graphics adaptor and all of that? You're looking for a straightforward 60xxx emulator to run on the CPU to drive all of those simulated chips?
 

foft

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Yeah exactly.

I got qemu working quite well. Also TomB offered some advice on how to get the uae jit ported, so I can try that later.

I have a cache problem I thought might be well known here. Linux is not told about 500GB of the DDR ram, so its for the FPGA or CPU to use. However if I mmap it via /dev/mem without O_SYNC I get slow access speed. Its like it doesn't enable the cache.

Are there any simple manual ways to enable the arm cache for a physical address? Its running as root so I have perms to do/call whatever.
 
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