Linux 0.11 rewritten in idiomatic Rust, boots in QEMU

https://github.com/Poseidon-fan/linux-0.11-rs

by arto • 10 days ago

138 141 10 days ago

github.com

rvz• 10 days ago

Nice project, with so many emojis at the start of every title of the README.

Wonder who could have done that?

fpauser• 10 days ago

;)

prologic• 10 days ago

I just compared this Rust implementation against the original C sources. Some ~50k SLOC (Rust) compared to maybe ~8-12k SLOC of C (depending on if you count headers). Why is the Rust implementation so much more complex and onerous?

binsquare• 10 days ago

I don't think it's rust

broknbottle• 10 days ago

More LoC means easier to quantify the impact when telling a story. The actual code quality may be lower but that’s the schmuck’s problem that comes after once promo is acquired.

newtonianrules• 10 days ago

I’ve never worked with Silicon Valley people before now, and now I get why so many projects are abandoned and rewritten when they could just use open source. The whole culture is promo driven.

3836293648• 10 days ago

Or, as others have already noted, it's only about 15k and the repo includes tools and test programs.

sudb• 10 days ago

One of the tradeoffs of Rust is its verbosity I think (in return for which Rustaceans would say you gain explicitness).

coldtea• 10 days ago

Verbosity compared to C?

Only in extra syntax constructs.

But Rust can absolutely do the same thing as C in fewer lines, especially when comparing each's standard features like string support.

9dev• 10 days ago

I absolutely despise that C convention if abbreviating absolutely every single thing as much as possible. Yeah yeah, that was necessary back in the day when memory was scarce and editors were awful, but come on those days were almost half a century ago by now.

Rust may be verbose, but at least you can read it without turning into a cynical greybeard subject matter expert first.

IshKebab8• 9 days ago

Rust is not a very verbose language. I translated (without AI) a medium sized program I'd written from Python to Rust and it was 10% longer. Hardly worth mentioning.

dminik2• 10 days ago

According to this breakdown: https://ghloc.vercel.app/Poseidon-fan/linux-0.11-rs?branch=m...

It's about 15k lines of code for the kernel and the rest is various utilities, libraries and programs that can run on the kernel.

dminik2• 10 days ago

Also, after a quick look at a few files, the rust version appears to be much more commented. Not sure if that makes up the extra several thousand lines, but surely counts accounts for some of that.

josephg• 10 days ago

If the readme is anything to go by, this doesn't look like it was written by hand. Codex if I were to guess. I wonder the coding agent "improved" the code.

The readme hints at the prompt:

It keeps the original system's semantics — what it does — while rethinking how it's expressed: stronger types, clearer module boundaries, idiomatic abstractions everywhere.

"idiomatic abstractions" would certainly bloat the line count.

rtpg• 10 days ago

kinda sad cuz 10klines you really get into "well I can just sit there and bang at the problem by hand" territory.

Sounds like a fun project....

pydry• 10 days ago

so, slop

kelnos• 9 days ago

If that's the case, I don't really get the purpose of this. It's presumably not a useful system for day to day computing. The main reason I could see someone wanting to build this would be as an educational exercise, and using an LLM to do it completely fails at that.

oalae5niMiel7qu2• 9 days ago

That's odd. Abstractions in other programming languages reduce the line count.

icemanx• 10 days ago

because of AI

ls-a• 10 days ago

I like how everyone has a different theory as to why

steveklabnik4• 10 days ago

For fun, I decided to take a look at a random syscall: fork.

* https://github.com/yuan-xy/Linux-0.11/blob/master/kernel/for...

* https://github.com/Poseidon-fan/linux-0.11-rs/blob/420152fdf...

The Rust is slightly shorter, though it also isn't organized in exactly the same way. The code isn't that different overall, creating and copying some data structures around, as you'd expect for a fork implementation of this vintage.

Maybe I got lucky, but I would expect that it's more of what other people said: this repository includes far more than the kernel.

Aurornis3• 10 days ago

This repo contains a lot of extra tools and userspace programs.

The majority of Rust the code in the repo is not for the Linux kernel.

BobbyTables2• 9 days ago

Longer isn’t always worse.

C code probably has no problem mixing and perverting int vs enum. Bitfields, structs, etc…

A rust program would define an enum and also implement handling of unexpected values (or consider them errors). Structs and bitfields would be more intentionally used.

Sure, Rust macros can avoid the boilerplate code, but overall line count may still increase a bit.

That said, I’d blame auto-generated code here as other commenters do.

torginus• 9 days ago

Onerous is a great word for this. I just checked the linked fork implementation, and basically all the lines of C code there is to the point, and does something useful. Most lines of Rust actually are there to satisfy some constraint of the language, do error handling or call into some other abstraction.

The post title describes this as 'idiomatic', but I have a feeling that actual Rust programmers might not agree on that.

This adds a ton of noise, and breaks up the flow of the 'happy path'.

I can reasonably expect what the C code will do, however with Rust, most code runs in 3 layers of nested lambdas, so I have no idea what's going without inspecting the definiton.

This also means that while Linux 0.11 could be compiled with optimizations disabled, and get decent performance, Rust relies on complex compiler transforms to generate OK code.

To be fair, these issues are not unique to Rust, as (for example) C++ isn't exactly better in this regard, but imo Rust could be a lot more pleasant to read or write for reason that have nothing to do with memory safety or borrow checking.

One of my opinions, is that 'smart' compilers often create long and implicit chains of reasoning that must be followed, making the code very hard to navigate without either an IDE, or having to run it straight up.

Complex type inference, and permissive import systems often lead to this, and these issues are not unique to Rust (and tbf, Rust dispatch is almost always static, so you don't have to deal with DI container BS)

xqb64• 10 days ago

Slopware?

bryanlarsen• 10 days ago

Presumably, but exactly the sort of project where slopware is appropriate. Nobody is expected to use it.

computerdork• 10 days ago

Haha, well, maybe a couple dozen grad students creating some unusual extension to the os:)

afdbcreid• 9 days ago

No, it's exactly the sort of projects slop is not appropriate. If you're going to use this in production, at least using LLMs (maybe) allows you to deliver faster.

Octoth0rpe2• 9 days ago

Nobody is expected to use it.

There's a certain ironic circularity to this comment given Torvalds' original email, describing his little project as:

just a hobby, won't be big

(of course, I agree with you, no one is going to use a vibe-coded port of 0.11. A port of the latest kernel however....)

xyst• 10 days ago

rewriting {PROGRAM} in rust is so fetch.

sajithdilshan• 10 days ago

Stop trying to make fetch happen

tialaramex• 10 days ago

They actually did make fetch happen. Once upon a time it was usual in Javascript to use a thing called XMLHttpRequest which despite its name isn't actually for XML, it's just that XML was a big deal when it was created. The replacement API for making normal HTTP requests is just named fetch, and it was "new" so long ago that popular web browsers had versions like 40 rather than 150.

That movie is so old it's entirely possible that it's just named "fetch" because that's a reasonable thing to call this feature and so it's a coincidence, but I do like to think that at least some people at WHATWG were quoting Mean Girls...

larkost• 10 days ago

I worked for Fetch Robotics (now defunct), and there were a bunch of people (especially in management) who would constantly reference the Mean Girls "stop trying to make fetch happen" line in company-wide slideshows.

A couple of times it was cute... but they took it too far in my opinion. And sadly the company was bought out, and now they too have decides to "stop trying to make Fetch happen" (yes, officially it was bought out, but not for the actual robots part).

weregiraffe• 9 days ago

Fetch is cringe and has been yeeted

mjhay2• 10 days ago

I used to like rust, but I feel like I’m being Pavlovian-conditioned to recoil at its mention now.

Krutonium• 10 days ago

I still like it. People are having fun playing with their toy and tool. I have no problem with that.

fsckboy• 10 days ago

People are having fun with AI coding, and I have no problem with that, but I am sick of hearing about it.

mjhay2• 10 days ago

I shouldn’t have been so negative. I still very much like Rust, but hearing about these AI rewrites constantly is tiresome.

minimaxir4• 10 days ago

Of all the tools in software engineering to be overpopular and overused, Rust is an instance where that is a very good thing.

Atleast people aren't AI rewriting things into PHP.

vlod• 10 days ago

Be careful, that sounds almost like a dare...

block_dagger• 10 days ago

I have the opposite feeling; I am liking Rust more and more and thinking most of the world's C code should be rewritten. It seems like a sweet spot of enforced memory safety, performance, and human/agent readability.

skor• 10 days ago

why rewrite if you can check for and fix bugs? If you are thinking of AI fixing bugs is less expensive

uecker3• 9 days ago

I think Rust is annoyingly complex and badly designed (although it has good parts) and this would be the same mistake as past pushs to move projects to C++ because "object orientation is clearly better", and as such also step towards more complexity that is difficult to undo again and therefor actively harmful. The better and more powerful approach to safety is proving correctness, which is already possible today but we lack good opensource tooling. Proofs can be added to existing code without introducing complexity.

anthk2• 9 days ago

Rust and C++'s overcomplex syntax are a nightmare to maintain and set.

Go should have been the C succesor long ago, at least for 64 bit machines. In the end It's from the same people of Unix/C/Plan9, so they know their flaws and reasons.

For C++ like performance, sadly there's nothing close to Rust, but Zig and Nim can be close and good enough. Inb4 "mah objects", just use Java or C# and forget C++ forever for OOP programming. The sooner, the better. If you like using C++ just as an improved C and hate templates and objects, just use it for QT5/6 and some performing games and applications. Go can handle the rest just fine.

What I'd love is to see projects like Cataclysm DDA:Bright Nights rewritten in Go, they could save tons of issues on compiling (Clang 11 here, a nightmware to compile) and running, because for an open world game using the GC would free tons of waste on references and objects ingame. Also it will compile much faster and it could be ported to most platforms with no efforts at all.

And I say this as an ScummVM user and sometimes I like debugging some old adventure and RPG games under it...

egorfine4• 9 days ago

Be careful. People are known to be lost once they start allowing poisonous thoughts like "most of the world's C code should be rewritten".

Aurornis3• 10 days ago

This is Linux 0.11 from 1991.

Someone is having fun with a side experiment that has no practical real-world implications.

This stuff is supposed to be fun and we should celebrate when other people are doing fun, pointless things like this. If you're interested then ignore it and move on. There's no need to get involved or comment if a project of no consequence is uninteresting to you personally

egorfine4• 9 days ago

Someone recently had a fun side experiment [1] that ended up killing a product.

[1] https://bun.sh/blog/bun-in-rust

kreco• 9 days ago

I find his comment interesting. It's just mundane feedback, but still a feedback.

Likewise, you could ignore his comment but decided to engage.

treyd• 10 days ago

Can you elaborate on what causes that reaction specifically?

IshKebab8• 9 days ago

It's pretty much the standard target for slop now, so now "in Rust" kind of implies "I just pointed Claude at it and have no idea if the result is any good, also it's an abandoned project."

Tbh I think Rust is popular and mainstream enough that it doesn't matter too much. There are still plenty of great Rust projects out there.

egorfine4• 9 days ago

The cult mentality of rust rewrites. Religion above all reason.

devy• 10 days ago

Docs full of emojis, this is another AI slop?!

Tangential note: there is already a community effort[1] to rewrite GNU commandline tools into Rust and Canonical shipped the rust version of the /bin/utils in Ubuntu 26.04 Resolute Raccoon by default[2] in their "oxidizing" initiative.[3]

PS: Linus Torvalds has confirmed that the existing Linux kernel will never be fully rewritten in Rust.[4] Let's see how well that statement age.

[1] https://github.com/uutils/coreutils

[2] https://canonical.com/blog/canonical-releases-ubuntu-26-04-l...

[3] https://discourse.ubuntu.com/t/carefully-but-purposefully-ox...

[4] https://news.ycombinator.com/item?id=41355731

lioeters• 10 days ago

As soon as Linus retires, there will be an initiative to rewrite the Linux kernel in Rust assisted by LLMs. Either that, or some company will fund a fork before that. Imagine, man pages full of emojis!

steveklabnik4• 10 days ago

Linus is supportive of Rust and uses LLMs.

The reasons to not have a full-Rust Linux kernel are over more important, real engineering things. (Platform support being the big one.)

irishcoffee• 10 days ago

What is “un-idiomatic” rust?

steveklabnik4• 10 days ago

With a project like this, I would expect that "idiomatic Rust" means "attempting to write as much safe code as is reasonably possible" rather than "translating the C to Rust directly".

broodbucket3• 10 days ago

I hate that 5 years ago I'd see a headline like this and think it was awesome, and now it's just "look at what someone's spent tokens on today"

encyclopedism• 10 days ago

Written by AI and not nearly as impressive at all. Such a shame because I thought someone had spent real time and effort producing this. The output is commoditised and now neither important nor precious. Damn near anyone could repeat it.

minimaxir4• 10 days ago

To paraphrase another comment (https://news.ycombinator.com/item?id=48900086), this project is fun and fun should be encouraged, as experimentation is what leads to more innovative things. The existence of this project doesn't take away from anything.

trollbridge3• 9 days ago

I wish people who do this stuff could at least write their own docs.

bigstrat2003• 9 days ago

I hate LLMs so, so much. They are destroying everything that used to be cool about programming. Or maybe the problem is that a bunch of people who don't actually like programming joined the industry, and now they have a tool that lets them phone it in even harder.

HackerThemAll• 9 days ago

"look at what someone's spent tokens on today"

Water, drinking water. Fsck these tokens.

richard_todd• 10 days ago

Honestly -- and I know this project is just a toy/fun experiment -- with modern AI, I think this is the correct approach to Rust-ifying projects. Just fork it and do an AI-assisted wholesale conversion, and run in parallel for a while to make sure all the regressions are found. Then you can compare to the original for benefits and drawbacks, and you get a more idiomatic code-base... instead of trying to convince longstanding projects to go into a half-rust Frankenstein model, which is what I usually see.

drnick1• 10 days ago

How does the performance compare?

jagged-chisel2• 10 days ago

How do the binary sizes compare? An original Linux 0.11 kernel vs. this oxidized version.

xedrac2• 10 days ago

If it's written with nostd, I'd expect them to be similar.

jagged-chisel2• 10 days ago

That is indeed the expectation. But what’s the reality?

bijowo1676• 10 days ago

The ultimate boss of Rust rewrites. Very happy that LLM assisted coding unlocks these kind of projects

globalnode• 10 days ago

rust evangelism is some people / youth of today trying to differentiate themselves from their parents, aka heavy metal of programming. its ok, its fun. i cant read their source code but i dont need to, theres a whole world out there of c/c++/python stuff that will get the job done faster and with less hassle.

dosisking• 9 days ago

Rock and roll is for people with limited musical ability. Heavy metal is for people with no musical ability. Your comparison of rust to heavy metal is apt and holds up well.

jsLavaGoat• 9 days ago

I wonder how long until we have an entire distro in Rust? I worked on this from the other end making drop in clones of bash, git, make, nftables, pf, iptables, and others, build on the Rust uutils.

fwiw, I never liked the ergonomics of Rust when coding by hand, but it is head and shoulders my favorite vibe coding language.

penguin_booze• 9 days ago

I'm wondering if anyone's attempting to revitalise the old Minix. Minix started out an educational software, from which, Torvalds admitted, he drew inspiration. Since then, they had higher ambitions. And now, from the last I heard, it has evolved into neither here nor there.

nineteen999• 9 days ago

Beginning with ME (Management Engine) firmware version 11 (found on Skylake CPUs and newer), Intel utilizes a customized version of the MINIX 3 microkernel operating system.

lproven2• 7 days ago

And now, from the last I heard, it has evolved into neither here nor there.

Minix 3 is a true microkernel Unix-compatible: it can run most of the NetBSD userland, for instance. It is probably the single most widely run Unix-like OS in the desktop/server world, as a copy runs in the hidden management engine inside every Intel CPU made in the last decade and a half or so. Whether the machine runs Windows, Linux, xBSD, macOS, it doesn't matter: deep inside it's running Minix.

But Intel committed nothing back and never even told the OS's creator. He only found out years later:

https://www.cs.vu.nl/~ast/intel/

shevy-java• 9 days ago

There is one thing I admire about the Rustees: they really try to change things everywhere, including at the bottom. Whether they succeed or not is secondary to that. Personally I dislike Rust syntax-wise, but the Rustees are very motivated folks. That is interesting.

larodi• 9 days ago

Just got downvoted few weeks ago for suggesting someone would soon rewrite Linux into Rust with LLMs and now he did, and this is topping HN.

Are you guys the same guys who read HM every day or some other completely new folk?

singularity2001• 9 days ago

The Redox operating system is a complete rewrite of operating system concepts in Rust.

Disclaimer, I worked on the Mac OS port.

Octoth0rpe2• 9 days ago

What does it mean to work on a port of redox on macos? The ability to compile it / build a disk image on macOs?

jedisct1• 9 days ago

What a waste of tokens.

lrvick• 8 days ago

See also: Asterinas is a full rust rewrite of a minimal modern linux kernel that can run a full on modern desktop environment.

hollerith• 8 days ago

Interesting. Can it run a mainstream browser?

lproven2• 7 days ago

No, not yet, but it's attracting interest. I wrote about it here:

https://www.theregister.com/software/2025/09/12/three-altern...

Linux 0.11 rewritten in idiomatic Rust, boots in QEMU

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