Integrating FreeBSD Libc as an External Library for Unikraft

[Adarshgupta1127]

Introduction

Hi everyone,

I'm Adarsh Gupta an aspiring GSoC 2025 contributor interested in working on the "Integrating FreeBSD Libc as an External Library" project. I have experience with C programming, Linux CLI, and GNU build tools, and I'm eager to contribute to Unikraft.

Project Overview

The goal of this project is to integrate FreeBSD Libc as an alternative libc for Unikraft, alongside the existing Musl implementation. This would provide developers with more flexibility when choosing a libc implementation and improve compatibility with FreeBSD-based applications.

Questions regarding the project are :

To better understand the project scope and challenges, I have a few questions:

1. Has there been any prior work or discussions on integrating FreeBSD Libc into Unikraft?
2. What are the key challenges in porting a new libc to Unikraft?
3. Are there any specific guidelines on how to structure external libraries in Unikraft?
4. Would there be performance trade-offs between FreeBSD Libc and Musl? If so, what aspects should I focus on while benchmarking?
5. Any recommended resources or past PRs I should review to get started?

I’d appreciate any insights, suggestions, or pointers to relevant documentation. Looking forward to engaging with the community and contributing to this project!

Thanks,
Adarsh Gupta

[StefanJum]

Hi @Adarshgupta1127. Let's move the discussion on Discord, since we don't check github discussions that often https://unikraft.org/discord.

To answer your questions:

1. I don't think there has been any work on integrating FreeBSD libc.
2. The porting will be very similar to what you see in the existent libcs (musl and newlib, mostly musl since it is the one used). You will need to go over the source files and add them to the build system, then add patches where necessary. The Config.uk and Makefile.* files are relevant. You can check this tutorial on the build system.
3. See the link above
4. Likely so. Everything comes with a trade-off. Regarding benchmarking, the most relevant way to do this would be to benchmark certain applications (e.g. redis, nginx, etc.) with both musl and the freebsd libc and see how they perform.
5. Again, see the resources at 2.