Add support for MidnightBSD

[laffer1]

It would be nice if you could add MidnightBSD to the list of supported operating systems.

Let me know if you need anything.

[jacob-carlborg]

I thought MidnightBSD was a distribution of FreeBSD, is that not the case? Are FreeBSD software compatible with MidnightBSD?

[laffer1]

Unlike GhostBSD, pfsense, opnsense, truenas core and so on, MidnightBSD has differences in userland and kernel, different features available in libc, etc. It also doesn't report as FreeBSD with uname -a

For example,
MidnightBSD stargazer.midnightbsd.org 3.2.3 MidnightBSD 3.2.3 #1n13168-9064b78add(stable/3.2)-dirty: Thu Apr 3 02:20:38 EDT 2025 root@stargazer:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64

About 60% of the time, you can fake something working by lying to configure about host and target but that's not always the case. Quite a few things don't work out of the box on MidnightBSD or require different patches. We have some extra things in libc like OpenBSD's ohash, clearenv, and extras from netbsd in libutil. base has mDNSresponder, netbsd spell(1) & progress(1), mined(1) from dragonfly, cpdup from dragonfly, different versions of base libraries, compilers, etc.

There's also a completely different package manager, mport.

We do merge a lot of code from FreeBSD into MidnightBSD, but it's not always 1:1. Right now, the stable/3.2 branch is roughly like FreeBSD stable/12 with modifications. master (current) 4.0 is roughly stable/13 but with an older LLVM release, and quite a few differences in libraries (versions and just what we use)

Having a runnable version on GitHub would make it easier to get patches upstreamed to some projects, so we can diverge more from FreeBSD.

[jacob-carlborg]

I see, thanks for the detailed explanation.

Let me know if you need anything.

One thing that would help is the necessary flags for running MidnightBSD in QEMU.

[laffer1]

This works
qemu-system-x86_64 -m 1024 -drive file=midnightbsd.raw,format=raw -net nic -net user

[arrowd]

MidnightBSD has differences in userland and kernel, different features available in libc, etc.

I always wondered what are they exactly and if it is worth it plaguing multiple upstream projects with #ifdef __MidnightBSD__.