oriscv

A RISC-V 32 instruction decoder/statistics generator written in OCaml. It can be compiled with OCaml 4.05.0 (the version distributed in Debian).

Dependencies

Only the stdlib and Dune for building. A Makefile could be made to do the same thing as this software is so simple.

Usage

To build and run oriscv, use the following commands:

$ dune build
$ dune exec src/oriscv.exe <instruction file>

oriscv reads hex instructions following their addresses, so you have to dump them first like this:

$ riscv32-unknown-elf-objdump -d <exe> | awk '/^[0-9a-f]+:/ {print $1, $2}' >out.dis

Warning

As oriscv stores read bytes in native OCaml integers (as they can store n - 1 bits of information), it does not work on 32-bits machines. To work on those, the program could be changed to use Int32 instead.

oriscv only supports a subset of RV32I for now (all of them except fences and CPSR-related instructions). Unrecognised instructions won't crash it (they will show up as illegal instructions once decoded).

Current features

• Number of instructions
• Proportion of branches
• Proportion of jumps
• Proportion of various pseudo-instructions (lla, la, far calls, li)
• Count chains of rd (ie. how many time a register is written to in an instruction window of size 8 by default).

License

This project is licensed under the Mozilla Public License, v2.0. A copy of the license can be found in the LICENSE file, or at https://www.mozilla.org/en-US/MPL/2.0/.