Extended Zcherihybrid to reflect that access is not allowed to CHERI instructions #464
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| @@ -324,7 +324,7 @@ it is not possible to disable CHERI checks completely. | |||
| endif::[] | |||
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| {cheri_default_ext_name} includes functions to disable explicit access to CHERI | |||
| registers. The following occurs when executing code in a privilege mode that | |||
| registers and instructions. The following occurs when executing code in a privilege mode that | |||
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I thought this was implicit because any CHERI instruction that uses a CHERI register is not possible, but happy to add this clarification.
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@arichardson I agree, it is implicit. For some CSRs, the text explicitly says "registers and instructions" (https://github.com/riscv/riscv-cheri/blob/main/src/riscv-hybrid-integration.adoc?plain=1#L446-L448) whereas for others the text only refers to registers. We might want to have that consistent. I am fine with either way.
If we go with only referring to registers, we might want to make it clear somewhere that this implies that code cannot execute CHERI instructions.
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The key question here is whether CRAM needs CRE, which it does, and that does not access CHERI registers.
Reading through the doc it's inconsistent about whether it's only registers or registers and instructions.
Maybe we need a better term, although I don't want to start renaming things now.
I'll have a go at improving the text....
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pushing to this branch resulted in a new PR (no idea why) but here it is: #474
The text in most cases only considered CHERI registers, but
CREalso prevents executing CHERI instructions.