Alternatives
Products that do what RISC-V core written in 600 lines of C89 does
- 1MA
RISC-V's compressed instruction (RVC) extension is intended as an add-on to the regular, 32-bit instruction set, not a replacement or competitor. Its designers intended RVC instructions to be expanded into regular 32-bit RV32I equivalents via a pre-decoder. What happens if we explicitly architect a RISC-V CPU to execute RVC instructions, and "mop up" any RV32I instructions that aren't convenient via a microcode layer? What architectural optimizations are unlocked as a result? "Minimax" is an experimental RISC-V implementation intended to establish if an RVC-optimized CPU is, in practice, any…
2022 · github.com
- 2AC
2022 · gist.github.com
- 3AP
2015 · github.com
- 4RV
2020 · github.com
- 5AR
2021 · guillaume.baierouge.fr
- 6AD
Hey HN! We are the founders of atopile. We’re building a tool to describe electronics with code. Here is a quick demo: https://youtu.be/7-Q0XVpfW3Y Could you imagine the pain of building an entire software product using only assembly code? That’s about how we felt designing hardware. We don’t currently have good ways to describe what we need, reuse existing designs and compile that description down to a product. We started atopile to fix this. atopile is an open-source language and toolchain to describe circuits with code. The compiler is here:…
2024
- 7IW
Sep 2025 · github.com
- 8XA
Feb 2026 · lyra.horse
- 9H1
This is a 16bit CPU+Minicomputer from pure 74 series logic. It has user/kernel modes, virtual memory, prioritized IRQ's and DMA. It has a full C compiler and a unix-like OS. It's still in development.
2023 · sol-1.org
- 10AM
2015 · github.com
- 11HT
2017 · blog.klipse.tech
- 12L8
2022 · github.com
- 13AA
I pretty much always have a kernel project going on, and have been that way for decades. Over the past couple of years, that's been Anos, which has gotten further along than any of my previous hobby kernels, supporting IPC, multitasking, SMP (x86-64 only right now) and running on real hardware. LLMs (mostly Claude Code) have been used during development, but I learned early on that it's not _great_ at code at this level, so I've restricted its use to mostly documentation and tests. There's _a little_ AI code in the user space, but I have a strict "no AI code" rule in the kernel itself. I…
Apr 2026 · github.com
- 14NR
Just released EGG, an emulator created for teaching Assembly and microprocessors (designed to suit the needs of the Microprocessors classes, at Universidade Federal do Paraná, Brazil). The emulator will support multiple architetures in the future, but currently only RISC-V is implemented.
2024 · github.com
- 15MM
Hi HN, I’m Dvir, a young developer. Last year, I got rejected after a job interview because I lacked some CPU knowledge. After that, I decided to deepen my understanding in the low level world and learn how things work under the hood. I decided to try and create an OS in C and ASM as a way to broaden my knowledge in this area. This took me on the most interesting ride, where I’ve learned about OS theory and low level programming on a whole new level. I’ve spent hours upon hours, blood and tears, reading different OS theory blogs, learning low level concepts, debugging, testing and working on…
Oct 2025 · github.com
- 16SX
2023 · github.com
- 17GI
Hi all! I'm going into my freshman year, and figured that the best way to prepare for the intro to programming Racket course would be to implement my own garbage-collected, dynamically typed, functional programming language in C ;) Anyways... here's the repo: https://github.com/liam-ilan/crumb I started learning C over the summer, so I still have a whole lot to learn... Any feedback would be greatly appreciated! :D
2023
- 18II
Hi HN, To truly understand how operating systems and network protocols work, I decided to combine two classic learning tools: the xv6 teaching OS and a from-scratch TCP/IP stack. I'm excited to share the result: my own from-scratch TCP/IP networking stack running directly inside the xv6-riscv (https://github.com/pandax381/xv6-riscv-net) kernel. The project uses a modern virtio-net driver, allowing it to run seamlessly in QEMU and communicate with the host machine. Key features: - From-Scratch Stack: The core is powered by microps…
2025 · github.com
- 19LC
I made a simple virtual machine that runs C in the browser.This project is made as an experiment to see if C can be learned easier if the lower level is covered in paralel. Sandbox: https://vasyop.github.io/miniC-hosting Tutorial part 1: https://vasyop.github.io/miniC-hosting/?0 More info: https://github.com/vasyop/miniC-hosting/blob/master/README.md Please support this project: https://github.com/vasyop/miniC-hosting/blob/master/support.md
2019
- 20IW
A fun toy memory allocator (not thread safe, that's a future TODO). I also wanted to explain how I approached it, so I also wrote a tutorial blog post (~20 minute read) covering the code which you can find the link to in the README.
Nov 2025 · github.com
- 21AS
2014 · github.com
- 22

Modified version of the original from http://www.projectoberon.com/ for use with the Oberon IDE - GitHub - rochus-keller/OberonSystem at op2-rv32
28d ago · github.com
- 23CI
If you work in C++, and you would like 2+ programs to share data structures (and/or native I/O handles a.k.a. FDs) among each other, there is a good chance Flow-IPC - will make it considerably less annoying to code than typical approaches; and - may massively reduce the latency involved. Those sharing Cap'n Proto-encoded data may have particular interest. Cap'n Proto (https://capnproto.org) is fantastic at its core task - in-place serialization with zero-copy - and we wanted to make the IPC (inter-process communication) involving capnp-serialized messages be zero-copy,…
2024 · github.com
- 24ER
Hi HN, This is a small RISC-V emulator I’ve been hacking on in Emacs Lisp as a fun weekend project. It started mostly as a way to better understand the RISC-V spec by implementing things myself, and also as an excuse to write more non-trivial Emacs Lisp. It currently focuses on RV32I and related basics, and is very much not optimized or production-ready. If you’re into RISC-V, emulators, or just enjoy seeing unusual things built in Emacs Lisp, feedback and comments are welcome Happy hacking!
Jan 2026 · github.com
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