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Re: [N8VEM: 18771] Motorola MC68020 Project Ideas
- To: n8vem@googlegroups.com
- Subject: Re: [N8VEM: 18771] Motorola MC68020 Project Ideas
- From: Alan Cox <etched...@gmail.com>
- Date: Sat, 4 Oct 2014 11:46:43 +0100
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> Imho, as we discussed the topic some time ago, the big PITA in such approach is how to write (or read-back if needed) this paging LUT without disturbing all other CPU activities
The designs I have seen bypass the MMU in supervisor mode. Even on very modern systems MMU reloading is somewhat disruptive so from the OS side its not a big deal. With a CPU cache that becomes even more true
I don't know how they switched the lut accesses around so you got mmio access to the LUT however.
Alan