whisker

A RISC-V emulator written in Rust, made with love. 💜

Overview

whisker is a work-in-progress RISC-V emulator that aims to provide a complete and accurate implementation of the RV64 ISA.

Development progress

Date	Milestone
Feb 13, 2025	First commit
Feb 15, 2025	Most of RV32 Integer instruction set implemented
Feb 24, 2025	Most of RV32 & RV64 compressed instruction set implemented
Feb 27, 2025	RV32 & RV64 atomic instruction set implemented
Feb 27, 2025	RV32 and RV64 multiply instruction set implemented

Building programs

whisker uses a cargo script for compiling programs. You must have a RISC-V 64 build toolchain in your $PATH. The script searches for the following toolchains:

• riscv64-elf-*
• riscv64-unknown-linux-gnu-*
• riscv64-unknown-elf-*

If you are a NixOS user, you can use the flake devshell to have a reliable environment.

Setup

1. First, compile the boot loader:

cargo cutie compile-boot-loader

2. Then compile a program:

cargo cutie compile <path to files...>

Compilation options:

• Pass compiler arguments with -C="<args>":

   cargo cutie compile program.c -C="-O3"

• Specify ISA extensions with -f:

  • f - float
  • m - multiply
  • a - atomic
  • c - compressed

  Example for multiple extensions:

   cargo cutie compile program.c -ff,m,a,c

• For programs with a main routine instead of _start, include the runtime:

   cargo cutie compile examples/runtime.s program.c`

Output files

All compiled binaries and object files are placed in the target directory.

Development setup

For NixOS users, a devShell is provided through the Nix flake:

nix develop

For Arch Linux users, install the following packages:

TODO: Document