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riscv / riscv-j-extension

Working Draft of the RISC-V J Extension Specification
https://jira.riscv.org/browse/RVG-128
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Some of PM CSRs address conflict with PMP CSRs #37

Closed gagachang closed 9 months ago

gagachang commented 1 year ago

According to pointer-masking-proposal, Some of PM CSRs are defined in the address:

PM CSR name | Address -- | -- MMTE | 0x3c0 MPMMASK | 0x3c1 MPMBASE | 0x3c2

But accroding to the privileged spec, these address have already been used for pmpaddr16, pmpaddr17, and pmpaddr18, respectively.

image

And the CSRs are already defined into QEMU: https://github.com/qemu/qemu/blob/master/target/riscv/csr.c#L4403 Is this pointer-masking-proposal in WIP? Or it has been deprecated.

martinmaas commented 9 months ago

The latest version of pointer masking no longer introduces dedicated CSRs but uses bits in existing CSRs.