"mfsBSD is a toolset to create small-sized but full-featured mfsroot based distributions of FreeBSD that store all files in memory (MFS) [Memory File System] and load from hard drive, USB storage device, or optical medium. It can be used for a variety of purposes, including diskless systems, recovery partitions and remotely overwriting other operating systems."

Martin Matuška is the creator of mfsBSD. He is also author of the original (2009) mfsBSD white paper, from which the excerpt above is taken. Upstream mfsBSD is maintained in the repository on GitHub.

This project integrates mfsBSD into the FreeBSD release tool set, creating an additional target of mfsBSD images (.img and .iso files) in /usr/src/release/Makefile. Prior to integration, mfsBSD only existed outside the FreeBSD release tool chain, and only -RELEASE versions were produced.

With this project, mfsBSD images will be available at the official FreeBSD release page. You will also be able to build mfsBSD yourself by invoking cd /usr/src/release && make release WITH_MFSBSD=1, which will then create mfsbsd-se.img and mfsbsd-se.iso at /usr/obj/usr/src/${ARCH}/release/.

The code is ready, and is currently under review. If you would like to get involved with the review process, please feel free to do so! Here is my revision.

Sponsor: Google, Inc. (GSoC 2023)