Bronzebeard is a simple, standalone assembler for developing bare metal RISC-V programs. It is designed for applications that stand on their own without relying on operating systems, frameworks, SDKs, or pre-existing software of any kind. This assembler supports the base 32-bit instruction set as well as the M, A, and C extensions (RV32IMAC).

Bronzebeard and its tools are implemented purely in Python. It has been written in order to be free from large, complex toolchains. This keeps the project portable, minimal, and easy to understand.


Much of modern software has accrued vast amounts of bulk and complexity throughout the years. Can useful software be developed without relying on any of it? That’s the question that this project seeks to answer. I believe that the rise of RISC-V provides a great opportunity to explore different methods of program development. Installing a full operating system doesn’t have to be a prerequisite to building something useful.

Check out the DerzForth project for further elaboration of this idea.


If you are unfamiliar with virtual environments, I suggest taking a brief moment to learn about them and set one up. The Python docs provide a great tutorial for getting started with virtual environments and packages.

Bronzebeard can be installed via pip:

pip install bronzebeard

Or, if you’d rather clone this repo and play with the examples:

git clone
cd bronzebeard/
# I'd still create and activate a virtual environment here
pip install -e .


First, create a text file with some RISC-V assembly source code in it:

add x1, x2, x3
add x4, x5, x6

Then, with Bronzebeard installed:

bronzebeard my_asm_file.asm

By default, the assembled output binary will be placed in a file named bb.out.


Bronzebeard’s tests are written using pytest:

pip install pytest

Once installed, the tests can be run via: