Roadmap?

[Timmmm]

In my head I've got a list of areas where the model needs work and the main priorities in each area. I thought it would be worth writing down as a roadmap. If this proposal is acceptable we can move it to a wiki page.

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Sail Roadmap

These are the main areas where work is happening. Indentation indicates dependencies.

Configuration

The implementation defined behaviour in RISC-V is near limitless, but only a small number of configuration flags are exposed by the emulator currently because they are very tedious to wire in.

Alasdair Armstrong is working on adding a native configuration system to the Sail language which will be a lot easier to use.

• Move from using sys_foo_enable() style callbacks to Alasdair's new native config system, once implemented. #495
• • Add flags for all the options that are currently hard-coded.
• • • Clean up the organisation of the code & files so it makes sense. It's a bit of a tangled web at the moment.
• Fix misaligned accesses and add options for common behaviours. #49
• Add extensions for the (un)privileged spec versions. #319

Testing & Infrastructure

Currently the code is not tested at all well. There's just a very old version of the riscv-tests in the repo. Ideally we would have unit tests written in Sail, and a wide range of ELF tests. It would also be beneficial to avoid requiring users to set up a cross-compiler, RISCOF, etc. to run the tests since that is quite onerous. But we don't want to store ELF binaries in the repo like we currently do. See Jessica's comment in #114.

• Switch to native Sail project file. #572
• Add callbacks for state change events. #494
• • Make RVFI a runtime option. #642
• • • Switch to CMake. #551, #647
• • • • Add Sail unit tests.
• • • • Test against the ACTs. #481
• • • • Test against a recent version of riscv-tests. See #114

Extensions

The two biggest missing pieces are Hypervisor and Vector Crypto. There are a number of smaller extensions that are missing too.

• Add support for Hypervisor. #612
• Add support for all the other extensions.

Verification Interface

Currently the only programmatic verification interface is RVFI-DII, but it only works over TCP and is quite limited. The goal is to expose a library interface, and a machine readable execution log.

• Add callbacks for state change events. #494
• • Add C++ library interface for instantiating the model, stepping it, and retreiving state change events.
• • Add support for logging state changes to a machine readable (e.g. Protobuf) file. #545

[jordancarlin]

Overall this looks great to me and I think having all of this explicitly written out is definitely helpful. Making this a wiki page that we keep up to date sounds good.

The list seems pretty extensive already. The only major thing that I can think of to add would be RVVI support under the Verification Interface section. I'll try and put together a full list of the extensions that are not yet supported to add to this. I have most of that list already from when I created the new list of supported extensions.

[Timmmm]

Added to the wiki: https://github.com/riscv/sail-riscv/wiki/Roadmap