riscv-emulator

(Note: This project is still on the process for completion!)

The project is built to learn RISC-V architecture as the purpose for me. It mainly comes from rvemu, which is a RISC-V emulator with Rust implementation. Also, some of the idea of CPU implementation is borrowed from riscv_em.

The emulator now supports fully RV64I, M, Zicsr, and Zifencei instructions. Most of the RV64C and some RV64A instructions are also supported.

Build and Run

To build the emulator:

$ make

Although the instruction cache isn't an esstential component for our emulator, but it could help to speed it with the fast path to decode an instruction! Note that the best configuration for the number of cache set and cache way will require more experiment, now they just simply set to 8 and 4. To build the emulator with I-cache:

$ make ICACHE=1

The emulator is also validated to run xv6-riscv, which is a simple UNIX operating system. You can use the provided binary by the following command directly:

$ make run-xv6

We also try to support running Linux on the emulator. Although it still need some work to boot completly. You can take a try with the following command.

$ make run-linux

If you want to run your own binary, the binary file in raw or ELF format are both supported. The emulator will check whether the input binary is under ELF format first, otherwise it will take it as a raw binary. You should notice that the process of ELF parsing now could be non-general and ugly, so feel free to report if you can't load your ELF binary! To load and run your binary on the emulator:

$ ./build/emu --binary <binary> [--rfsimg <root filesystem image>]

Compliance Test

The riscv-arch-test is applied to check if implementing the specifications correctly. We can pass RV64I, RV64M, and RV64C(except cebreak) now.

You'll need riscof to run the test. The following command could be use to simply install it. Please take a look at RISCOF document if you find any problem when installing it.

$ pip3 install git+https://github.com/riscv/riscof.git

After installing riscof, You can run the compliance test by the following command.

$ make run-compliance

Instruction Unit Test

The riscv-tests is also applied to check if implementing the specifications correctly. We can pass RV64UI, RV64UM, RV64UC and RV64UA now. You can run the riscv-tests by the following command.

$ make run-riscv-tests