riscv-arch-test VS riscv-formal

git: https://github.com/riscv-non-isa/riscv-arch-test.git commit: 6d87f30 (current master)

There's also https://github.com/riscv-non-isa/riscv-arch-test, which I think is using similar tests to riscof (some generated by riscv_ctg) just an older framework to run it all.

Prior notice, I work for a professor and he wants me to test/verify a riscv simulation model, which is programmed in VHDL. He referred to the https://github.com/riscv-non-isa/riscv-arch-test , to look up how I have to set up a test.

This is the current compliance test repository. https://github.com/riscv-non-isa/riscv-arch-test

Have you tried running the RISC-V architectural test suite: https://github.com/riscv/riscv-arch-test? It should fit pretty nicely with your test system, each test generates a signature that needs to be checked against an expected output.

There are official RISC V tests you can run: https://github.com/riscv/riscv-compliance

You might be able to hook up your simulator to risc v-formal https://github.com/SymbioticEDA/riscv-formal

Then we have RISC, which wrote their own formal verification toolchain here. They just generate Verilog with a Python script. AFAICT this would be really hard to adapt to an assembler. Fortunately the ISA is simple to implement.

Your question is certainly not dumb; on the contrary, it is very important! I suppose the developers are responsible for verifying the formal verifier and ensuring it covers the spec. Maybe there is a way to formally verify the formal verifier? Either way, I must give a shout out to the riscv-formal project and its contributors; the project was instrumental to the development of Lion.

Not trying to put words in your mouth, but I do want to clarify something for this audience: the bound in the BMC done by the riscv-formal suite is on the number of cycles, not on the number of bits. Case in point, when you try to BMC the (M)ultiply extensions with the riscv-formal suite, you're actually not allowed to use multiplication because the state space blows up: https://github.com/SymbioticEDA/riscv-formal/blob/master/docs/rvfi.md#alternative-arithmetic-operations

Use riscv-formal. It will save a ton of headaches trying to track down a bad instruction. It can generate a module that does checks on the fly during normal sims.

I recommend SymbiYosys for formally testing your CPU before ever placing it into a simulation. You can use the riscv-formal property set to get you started, but I'd personally go for an inductive proof of some type and the riscv-formal property set may not get you that far.