(A better, more considered, response than I gave yesterday.)
Alastair Reid's article "How to improve the RISC-V specification" makes some great points: namely that the RISC-V specification needs improvement, (implicitly) that this work is worth doing, and that testing is integral to specification. These are all great points.
However, a new specification effort for RISC-V requires a much greater effort.
The core document certainly needs to be rewritten with better structure, a more formal presentation of each 'instruction,' better clarity on what it is saying, and fixes to numerous errata. The harder 'fix' requires resolving the tension between its two readerships --- the implementors who must process instructions according to the requirements of the spec versus the coders who need to know what they can expect from the environment in which their instuctions are processed. (The 'unpriviledged' element in the subtitle of the spec is the code being executed.) Problematically, this tension might not be resolvable: since the core instuction set has no side effects and no requirements can be placed on how implementations are made, the spec inherently has no way to express knowledge of whether the code has been processed correctly! Fun.
A new specification effort has a bigger task than fixing, as best as possible, the current document. Alastair Reid's article mentions needing to integrate testing more centrally into the specification. There is also the need to think of this core spec as the foundational document on which to build the whole suite of RISC-V specification documents. A new spec also needs to cater to the even wider readership, beyond 'implementors' and 'coders,' that accompanies projects with wide-spread success. For example, the spec ought to serve companies or governments in their procurement contracts, so they can express what is meant by deliverables which are conformant with the specification. Ideally, this wider readership under consideration would also include 'students,' that is smart people who have less a priori knowledge of the domain than that which the original 'manual' was able to assume.
This is all a lot of work, which would be of great benefit to the community but which no one in the community has any reason to, or really could, take on. Ideally, the RISC-V Foundation would scope out the work, take a position on what parts of the effort were worth pushing for, and then make that happen.
Alastair Reid's article "How to improve the RISC-V specification" makes some great points: namely that the RISC-V specification needs improvement, (implicitly) that this work is worth doing, and that testing is integral to specification. These are all great points.
However, a new specification effort for RISC-V requires a much greater effort.
The core document certainly needs to be rewritten with better structure, a more formal presentation of each 'instruction,' better clarity on what it is saying, and fixes to numerous errata. The harder 'fix' requires resolving the tension between its two readerships --- the implementors who must process instructions according to the requirements of the spec versus the coders who need to know what they can expect from the environment in which their instuctions are processed. (The 'unpriviledged' element in the subtitle of the spec is the code being executed.) Problematically, this tension might not be resolvable: since the core instuction set has no side effects and no requirements can be placed on how implementations are made, the spec inherently has no way to express knowledge of whether the code has been processed correctly! Fun.
A new specification effort has a bigger task than fixing, as best as possible, the current document. Alastair Reid's article mentions needing to integrate testing more centrally into the specification. There is also the need to think of this core spec as the foundational document on which to build the whole suite of RISC-V specification documents. A new spec also needs to cater to the even wider readership, beyond 'implementors' and 'coders,' that accompanies projects with wide-spread success. For example, the spec ought to serve companies or governments in their procurement contracts, so they can express what is meant by deliverables which are conformant with the specification. Ideally, this wider readership under consideration would also include 'students,' that is smart people who have less a priori knowledge of the domain than that which the original 'manual' was able to assume.
This is all a lot of work, which would be of great benefit to the community but which no one in the community has any reason to, or really could, take on. Ideally, the RISC-V Foundation would scope out the work, take a position on what parts of the effort were worth pushing for, and then make that happen.