Show HN: I integrated my from-scratch TCP/IP stack into the xv6-riscv OS

53 pandax381 4 8/26/2025, 6:24:30 AM github.com ↗
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 (https://github.com/pandax381/microps), a TCP/IP stack I originally wrote to run in user-space as a personal project to learn the low-level details of networking.

- Kernel Integration: This project ports microps from user-space into the xv6-riscv kernel.

- Socket API: Implements standard system calls (socket, bind, accept, etc.) to enable network application development.

- User-level Tools: Comes with a simple ifconfig command, plus tcpecho and udpecho servers to demonstrate its capabilities.

This has been a fantastic learning experience. My goal was to demystify the magic behind network-aware operating systems by building the components myself.

I'd love to hear your feedback and answer any questions!

Comments (4)

dancek · 2h ago
Awesome work! Thank you for showing it to the world!

I've considered writing a network stack myself. It's much more complex than most people can imagine. We have great tooling for TCP and that makes people believe it's simple technology. It's not.

Tony_Delco · 2h ago
This is amazing work. Most people don’t realize how much effort and depth there is behind writing a TCP/IP stack and plugging it into xv6 with virtio-net and sockets. Huge respect for making it public. Projects like this are gold for those of us who love low-level systems.
lesser-shadow · 3h ago
Are you using any RISC-V extensions? If so, which? I couldn't find this information on the xv6 project page. It would be cool if you could run this project in bare metal.
theosp · 4h ago
Well done! Thank you for sharing