seL4 VS InitWare

> People like to snob Unix but the fact is: the world runs on Unix.

The world you are aware of runs on it.

> Can we really do that much better or is it just hubris?

Yes. Have a look at seL4[1] and Barrelfish too[2], even though that's no longer active. seL4 in particular is powering a lot of highly secure computing systems. There is a surprisingly large sphere outside of Unix/POSIX.

[1] https://sel4.systems/

[2] https://barrelfish.org/

There are also RTOS-capable microkernels such as seL4[0], with few but extremely fast syscalls[1]. Note times are in cycles, not usec.

0. https://sel4.systems/

1. https://sel4.systems/About/Performance/

https://sel4.systems

Working on a number of platforms, verified on some. Multicore support is an ongoing effort afaict.

On OS built on this kernel is still subject to some assumptions (like, hardware working correctly, bootloader doing its job, etc). But mostly those assumptions are less of a problem / easier to prove than the properties of a complex software system.

As I understand it, guarantees that seL4 does provide, go well beyond anything else currently out there.

Take a look at this: https://sel4.systems/

It's probably have to be seL4 (https://sel4.systems), running on some fully OSS hardware.

There are question marks over much of available RISC-V chips due to chinese producers, so maybe OpenPower based hardware?

Plus, the entire system (motherboard, etc) would need to be manufactured using a good supply chain.

Hmmm, this has probably all been thought through in depth before by others. :)

You can use it to (mostly) validate small snippets are the same. See Alive2 for the application of Z3/formalization of programs as SMT for that [1]. As far as I'm aware there are some problems scaling up to arbitrarily sized programs due to a lack of formalization in higher level languages in addition to computational constraints. With a lot of time and effort it can be done though [2].

1. https://github.com/AliveToolkit/alive2

2. https://sel4.systems/

Formal methods. This is not in most general-purpose programming languages and probably never will be (maybe we'll see formal methods to verify unsafe code in Rust...) because it's a ton of boilerplate (you have to help the compiler type-check your code) and also extremely complicated. However, formal methods is very important for proving code secure, such as sel4 (microkernel formally verified to not have bugs or be exploitable) which has just received the ACM Software Systems Award 3 days ago.

Today we'd look at seL4.

Fear not. They get to be part of the future too.

> Yes indeed, I should've expanded to requiring user namespaces and other kernel magic I can't expect from any random box i wanna work on.

That's fair, do have to make sure to avoid to modules that do user systemd services.

Longer term, though, I am hoping https://github.com/InitWare/InitWare will help with the userland part. And I hope to personally help with things like

https://lists.freebsd.org/archives/freebsd-arch/2022-January...

https://lore.kernel.org/lkml/f8457e20-c3cc-6e56-96a4-3090d7d...

to get us more sane cross-platform system calls.

I know, but support is still in FreeBSD. My big long term plan is:

1. Work on FreeBSD cross in Nixpkgs, because I need a way to pin forks and run nice tests without going insane. (We already have NetBSD cross.)

2. Rig up a booting image that uses https://github.com/InitWare/InitWare, the fork of systemd.

3. Add support to CloudABI in initware.

4. Bang on drum for other OSes and upstream systemd to implement this stuff we can can good portable abstractions -- I think this is our best shot to get "portable containers".

I haven't bothered to have a beef with systemd, but some of us have discussed https://github.com/InitWare/InitWare to support non-Linux kernels. That would be really fun.

I'm the first to admit that I'm ignorant of the facts here, but seeing that a systemd fork ran on OpenBSD for the first time two months ago does not give me confidence that it's "an option" in the sense that you can trust it to work well.

And to be pedantic (this is an OpenBSD thread, after all), it's not "systemd", it's a fork of systemd called "InitWare", and the GitHub repo describes it as "alpha software".

Someone also pointed out in the discussion you linked that it doesn't seem to include journald. Here's a relevant PR: https://github.com/InitWare/InitWare/pull/27

The project GitHub is found at https://github.com/InitWare/InitWare

You may have heard of InitWare https://github.com/InitWare/InitWare. Discussions, note that one of the titles is misleading: