FTL: A new operating system for clouds

7 hours ago (ftl-os.org)

https://github.com/nuta/ftl

Is it just a hobby, and won't be big and professional like gnu?

What does "OS" for clouds mean?

Does this mean you still delegate to something like KVM/paravirtualzation for your device models, but your FTL guest OS can run multiple secure workloads inside a VM?

Or are you designing a custom OS from the ground up to run on native hardware? What constraints are you putting on hardware support to make this a tractable that's not re-implementing all of the stuff that linux has? I assume that's why it's advertised for the "cloud", because you know a priori the deployment machines you're gonna run on? Or is hardware support known by kernel devs to be a (relatively) trivial problem in the OS space, compared to the user-facing features (like processes, scheduling, memory management, etc)?

Or is the bet that microkernel = win = can implement everything linux has and more?

I'm curious about the eventual end goal for the project is, not just what currently exists (as otherwise the answer currently seems to be sentence 1)

I just make agents generate assembly for my app and my hardware and boot directly into that.

  • Is this written in jest? Because it's very likely where the future of computing is heading. See https://www.youtube.com/watch?v=kZRE7HIO3vk; a lot of people were nagging on Casey because he implied that software was more efficient back when everyone "wrote their own kernel" and how "impossible it would be today". He even mentions how awesome it could be if every game came with it's own bootable USB. Now back then it truly was unthinkable, but today we're edging ever closer to that reality.

    For instance, I have a working microkernel written in a Lisp dialect for embedded devices. Compiled to native machine code. 100% LLM generated. ~70k loc. In benchmarks it outperforms most other embedded kernel projects by a significant margin. And it only took around ~$1500 in tokens (API costs all included).

    • A problem with this approach is that it would put a large burden on the application developer (or development system) to support other devices (or services) than initially planned.

      Of course, it would be possible to add new drivers only when necessary, but that would also allow for security problems.

      So, in theory it might work, but in practice it would require quite a bit of thought.

      7 replies →

    • When AI proves theorems, it uses divide-and-conquer approach just as humans - it breaks a big theorem into lemmas and tackles lemmas one by one.

      An alternative approach where it is just one big-ass logical expression is just not better.

      Same thing with code, I think - you need some intermediate results like a calling convention, helper subroutines, etc.

      A sufficiently powerful AI can do compilation "mentally" - i.e. producing machine code conforming to a specific calling convention. It can also decompile machine code. But you, obviously, don't gain anything doing it this way, if there's one-to-one correspondence between high-level code and machine code. You might as well just write high-level code.

      I really hope that software becomes more efficient. But I don't think that it can only be done by generating machine code directly.

Sounds kinda like gVisor more than Unikraft? With a maybe-faster intercept path?

  • That was my first thought. I think adoption will increase if projects will have a clear FAQ about prior / related work, and not leave this to the reader (human or AI) to figure out.

  • I think it's a kind of like both? it runs as its own guest, but instead of implementing syscalls that are 1:1 with linux, it looks like linux runs as a library, and uses a different more pared down set to take a normal sys call path to the guest. so my guess is not cheaper at all, since instead of the gvisor syscall->vmexit for the common path, its maybe process->sys call to guest->vmexit to hypervisor.

FTL v0.1.0 was just released, adding async Rust support (multi-thread Tokio runtime) and lots of missing pieces in the Linux compatibility layer.

(not my project)

So it's a microkernel...ish? And it runs Linux programs and supports enough features to serve its own website. Excellent; I hope it takes off.

  • It's a classic exokernel. Which unfortunately feels like there's some secret cabal paying those writing operating systems textbook writers to explain poorly.

    Basically the point is rather than keeping the absolute minimum in the kernel, you keep the minimum needed to multiplex the hardware with the fewest abstractions possible. So stick a network driver in there, sure. But does the TCP stack need to be in there? Stick a disk driver in there, but does the VFS need to be in there?

    Then you add security so that the fast path doesn't need to go to a user space abstraction service. You have something like bpf so that processes only get the packets that correspond to the ports they've opened, directly from the kernel device driver. Your FS service gives out revocable capabilities to the disk blocks corresponding to files a process was able to successfully open, etc.

I would like something Unix-y and Linux-compatible that follows the principle of least authority.

Linux namespaces and cgroups and seccomp are a mess ... but actually they are probably more functional than what OS X or Windows provides.

I wonder if we can do better. But maybe not in this project?

This is actually interesting, since most containers don’t actually need an independent kernel at all. Of course, this moves a container a lot closer to effectively being a chroot jail (but that’s a good thing) + having some capabilities taken away.

Wrong. That would be https://github.com/H4vC/oh-my-uefPi

A single BOOTX64.EFI that boots a Hyper-V VM straight into a chat prompt, streams replies from an OpenAI-compatible /v1/chat/completions endpoint (DeepSeek by default), and boots whatever the model is asked to: Omarchy, netboot.xyz, or any UEFI image at an http(s) URL. No OS, no history. Dressed up like omp, for the memes

parts of the kernel design remind me of zircon (handle oriented objects, vmo's, and so on), but then various lines are cut in different places (kernel knows of threads but not processes, maybe handles slightly higher level networking)

Is this a unikernel? Your ASCII art diagram is broken.

  • It's an exokernel. It's kind of like if you modified a hypervisor specifically for running unikernels instead of classic VMs.

  • having looked at the briefly, is really a kernel that's meant to take system calls. I think the unikernel terminology is kinda broken. it's explicitly pared down to talk to a hypervisor rather than supporting a lot of hardware drivers. is a unikernel something you link in like a library? then its not. is a unikernel something that's intended to support a single process? then sure.