Re: comments on PMP enhancements
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Two quick comments:
- I am assuming that this is a proposal to replace the existing "enhanced" PMP proposal, rather than an "enhanced-enhanced" PMP proposal.
- do we ever need to allow Write_Only and Write&Execute regions? OR can we continue to disallow them, except for the specific shared RW/RO regions defined by the enhanced proposal
( which in this case is when MML=1, M=0 as opposed to the enhanced proposal of MML=1, L=0)
Separately, there is a proposal to have an S-PMP, which further filters addresses but allows Smode to configure them.
It would be useeful to consider whether they would be completely separate CSRs or they could overlay the existing ones ones somehow.
Even if they are totally separate, it would be useful to ensure the encodings were similar enough that the same HW (with simple external wiring changes) would work for both.
On Fri, Feb 14, 2020 at 12:57 PM John Hauser <jh.riscv@...> wrote:
Nick Kossifidis wrote: