Re: [Milkymist-devel] [Milkymist port] virtual memory management

[Martin Husemann <martin%duskware.de@localhost>]

On Mon, Jun 03, 2013 at 08:34:37PM +0000, Eduardo Horvath wrote:
> So your MMU doesn't support multiple address space IDs?  That sux.  That 
> means you need to blow away the entire MMU each time you switch processes.
> 
> If you do have ASIDs, I like to reserve one for the kernel.  That way you 
> don't need to share the address space with userland.  

Let me second this - make the MMU know address space IDs and reserve one
(typical choice: 0) for the kernel.

Then either provide (priviledged) load/store instructions to access
foreign address spaces (providing the other ID in a cpu register), or
add a mmu register to load a special address space ID and add
load/store-with-that-other-id instructions.

Martin