Re: lua - running bytecode from an external ram space

[Rob Kendrick <rjek@...>]

On Thu, Jul 14, 2011 at 10:12:05AM +0300, Bogdan Marinescu wrote:
> > Does that processor have something like the memory protection unit on the
> > arms?  You could easily change the Lua allocator to use your own function
> > that 'allocates' from a protected region and use the fault handler to do the
> > access.
> 
> I don't know of any MCU with a MMU. 

I first suggested just this technique earlier in the week :)  Larger
STM32s have an MPU (a heavily cut-down MMU) that may be able to do this
paging as you suggest: poor performance may be acceptable if you don't
need to query it often.  Some of NXP's LPC range have a full ARM9-style
MMU that you can use if you want.  Or there's the option of selecting a
MCU with an external memory bus.

The alternative might be to augment the compiler to generate function
calls for memory accesses, but I suspect this would be the ugliest of
hacks.

B.