JSLinux

6 days ago (bellard.org)

Fabrice does a great job at building these self-contained pieces of software which often grow to have lives of their own. As a lesser known example, JSLinux's terminal emulator was forked a few times and is now known as xterm.js, which has become the predominant web embeddable terminal emulator.

This all comes full circle, because now I'm building a true successor to JSLinux that's way faster because I've natively compiled the kernel/userspace to wasm, and of course I'm using xterm.js for the terminal emulation.

If you like buggy demos that probably shouldn't be shared yet, you should check out https://linux.tombl.dev, but note that it's currently just a busybox shell and nothing else, so I hope you're good with `echo *` instead of `ls`.

  • I like to say Fabrice creates side projects that others spend their entire careers maintaining.

    I knew about QEMU, ffmpeg, his LTE stuff, and QuickJS. I had no idea xterm.js started with him too.

  • This produces

            attempted to munmap
            ------------[ cut here ]------------
            WARNING: CPU: 3 PID: 36 at kernel/exit.c:812 0x00000000
            CPU: 3 PID: 36 Comm: sh Not tainted 6.1.132 #
            Stack:
                at vmlinux.o.__warn (https://linux.tombl.dev/dist/vmlinux-NLTKI6YG.wasm:wasm-function[278]:0x17655)
                at vmlinux.o.warn_slowpath_fmt (https://linux.tombl.dev/dist/vmlinux-NLTKI6YG.wasm:wasm-function[279]:0x1772b)
                at vmlinux.o.do_exit (https://linux.tombl.dev/dist/vmlinux-NLTKI6YG.wasm:wasm-function[329]:0x1985e)
                at vmlinux.o.task_entry_inner (https://linux.tombl.dev/dist/vmlinux-NLTKI6YG.wasm:wasm-function[154]:0x12249)
                at vmlinux.o.task_entry (https://linux.tombl.dev/dist/vmlinux-NLTKI6YG.wasm:wasm-function[153]:0x12155)
                at self.onmessage (https://linux.tombl.dev/dist/worker-MHWHWELT.js:151:53)
            ---[ end trace 0000000000000000 ]---
    

    on any command

    • yep, that's to be expected, this is a very wip demo. I'm implementing exec() support now, so currently only shell builtins work.

      6 replies →

  • Awesome, I suppose it's more energy efficient then jslinux and can be run on iOS, it might be a good alternative for A-Shell or iSH. I tried it on my a MacBook, but the keyboard input doesn't register.

    • Thanks for pointing this out, I've deployed a fix. One of my goals for the project is to create a useful computing environment on top of any arbitrary locked down platform, so I'd love to turn it into an iOS app at some point.

      1 reply →

Fabrice is amazing. The amount of stuff this guy has built is utterly incredible.

If I built any one of the things he's built (ffmpeg, qemu, tinyc) I would never stop bragging about it. Instead, he just keeps hacking on other cool stuff.

  • Yeah why don't we learn what he wants and just give it to him, in return he'll properly rewrite all the broken shit we have. Phones, operating systems, desktop environments, countries, appstores, etc.

    • I can imagine he wouldn't be interested in any of that. The joy of hacking only emerges when there are no external demands. That's why work sucks and you need to pay people to work for your demands.

      3 replies →

    • This is literally a brilliant idea. This guy needs a Macarthur grant now. Even if he rewrites half of all the broken shit we have, (and takes all of 20 years to do it) the world will be a better place. Except for _ which will always be a ___ hole.

      4 replies →

    • > in return he'll properly rewrite all the broken shit we have

      Probably that's exactly what he doesn't want.

  • I love this guy. Half of the world's android development has been made easier due to his courtesy, and it's getting more (his qemu is ubiquitous)

  • Also the same person who wrote LZEXE, which might be familiar to people who used DOS.

  • I'd love to know how he chooses what to work on. I wonder if he just follows his interest?

Considering the extremes of prolific developers gives interesting contrast to dogmas such as "functions/files should never be above x lines", where `quickjs.c` is 50k lines and has functions that are hundreds of lines long:

https://github.com/bellard/quickjs/blob/master/quickjs.c

(Obviously different approaches suits different circumstances.)

  • The answer is simple: Bellard can recall all 50K lines of context, while most can't. I too happen to have a larger working memory and only later realized that my threshold for files and functions is way higher than most others. The dogma is only required when the file is to be read and written by multiple people.

    • I have written long methods and will do so again and I wouldn't say it's because I have larger working memory or some other supposedly superior attribute. Some methods are just a long series of steps that you can just write one after another. Reading it from top to bottom is exactly as difficult/confusing/whatever as reading them as separate methods would be (assuming you put short comments in the same places where you would otherwise break it up). I think people just don't want inexperienced programmers to do that because they'll end up with tons of mutable state spanning the whole thing, and it's easier to tell them to break it up into methods than to explain what you mean by mutable state and limited scope.

      1 reply →

    • I feel like this is an underrated superpower. I don't have it - my digit span[0] is about 3, well below normal, so I've always felt that while I'm pretty smart (and managed to get a scientific PhD at an Ivy, so my brain's doing /something/ right), I've always felt like I'm driving a Ferrari but the windows are all blacked out and I'm looking through a tiny hole.

      [0] https://en.wikipedia.org/wiki/Memory_span

    • tbh working on one file is most often much more ergonomic for me. Depends entirely on the sw architecture of course.

  • I work on that codebase (we forked it off to QuickJS-ng) and while daunting at first, it's somewhat easy to work with, with the right editor! Many of them choke on such a large file, alas.

    While it being a very large file, it's sorted somewhat semantically, so it's easy to work on adding a new iterator method, for example, since they are all close to each other.

  • Because people you’re working with are not Fabrice. It is easier to say “don’t do X at all” than explain when it is safe to break the rule.

    Also, this would depend on language of choice. JVM, for example, might not inline function above certain threshold of bytecode instructions.

  • Rather one long function than does one thing well than multiple function that are strongly coupled and difficult to reason about. Programmers who apply dogmas can be harmful.

  • I think this person creates these marvels entirely by himself. There is no need for collaboration rules.

  • In the age of advanced IDEs/text editors with goto definition, find references/usage, fuzzy search, etc, what is even the point of multiple files?

    I never navigate by files in my code bases, it's all based on search and "jump to" type navigation.

I played around in Windows 2000 for the first time in 20 years. I know nostalgia can be blinding, but I would go back to that UI in a heartbeat. The uncluttered taskbar, the simple start menu that isn't full of useless recommendations and ads—such a joy!

I have to say there are some extremely talented, creative and productive "software artists" or ICs coming out of France. Not sure if that's a French thing (the Ecoles or whatever) or something else, but it's noticable.

  • Bootlin is a French company and they are a major open source contributor. I worked with them and I recommend them.

    French tech used to have a reputation for Renault old car quality, but I did not see it. Even in Renault and Citroen I came to admire them. On the other hand working with German SE is hard because they are incredibly set on not invented here. My generalisation for whatever it is worth.

    In general the issue of Europe tech scene is simple: we suck at selling and optimise for resource efficiency(competitive salary means never pay above rate no matter what). Americans optimise for growth and will risk paying for higher so they can amortise costs with growth.

    On a final note, where I come from there is lots of sneer that France is a dump due to immigration. While that is a point of view, it is definitely true they have also brain drained their colonies and have very capable productive individuals coming from there. Myself I had my master’s tutor from cot-de-Ivoir and in bootlin also worked with top of the shelf engineers that have non francophone names.

  • Can you name some that invite comparison with FB?

    • I'd do less comparison and more recognition. Some of these are kind of old or from the past and I'm no expert and the list is very incomplete but:

      Jean Ichbiah - big contributor to Ada

      Alain Colmerauer - creator of Prolog

      Jean-Marie Hullot - iCal, iSync, NeXTSTEP GUI builder, CTO of Applications at Apple in early 2000s

      Philippe Kahn - founder of Borland, inventor of first camera-phone

      Olivier Fourdan - creator of Xfce, big contributor to Wayland

      5 replies →

JSLinux was our inspiration for creating Endor (https://endor.dev) and his qemu work is also powering a lot of other Wasm-related browser projects

  • Are there any open details on how the VM / container / WASM-native approaches are implemented?

    • Not right now, we should write a blog post, but we are still behind on the docs. VM and containers use V86, while wasm-native are generated using Emscripten.

      1 reply →

Fabrice is an amazing programmer, and does cool things. He is an inspiration to us all.

My dream is have a in browser nixos vm on wasm. If I could have a bare vm, I can bootstrap it easily with a nixos config. From there I can start thinking about running web services in browser tabs instead of physical hardware.

  • Pretty sure this is possible already... What's stopping you?

    • I’ve tried to set this up and get a little bogged down on some of the finer points of compiling nixos to wasm. It’s not very straightforward unfortunately :/

Good.

Only wayland RISC-V 64bits binaries from now on, even for the web.

We don't need anything else anymore.

This is amazing! But beware admin, it seems that the RAM can be hijacked and increased...

JSLinux is too slow to be used for anything.

Where is the complete source code for this?

for now I get a kernel panic due to NoScript.

But does this support recursion? I'd like to run JSLinux in my browser and then point its Browser to https://www.bellard.org/jslinux/ which then starts another JSLinux which opens the browser on JSLinux which ...

JSLinux isn't another Linux but a landmark of postmodern philosophy, and OP most def forgot to credit Baudrillard.

crazy cool.