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Blog post: The Linux kernel is just a program (serversfor.dev)
submitted 8 months ago by zknd@lemmy.world to c/programming@programming.dev
15 comments fedilink hide all child comments

I’ve been working on a "Linux Inside Out" series and wrote a post that might interest folks here who like low(ish)-level / OS internals.

The idea is to dissect the components of a Linux OS, layer by layer, and build a mental model of how everything fits together through experiments.

The first part is about the kernel, in the post I:

  • take the same kernel image my distro boots from /boot
  • boot it directly with QEMU (no distro, no init system)
  • watch it panic
  • write a tiny Go program and use it as PID 1
  • build a minimal initramfs around it so the kernel can actually start our process

The goal isn’t to build a real distro, just to give a concrete mental model of:

  • that the Linux kernel is just a compressed file, you can boot it
  • without anything else
  • what the kernel actually does at boot
  • how it hands control to userspace
  • what PID 1 / init is in practice
  • what is kernel space vs user space

Link: https://serversfor.dev/linux-inside-out/the-linux-kernel-is-just-a-program/

I’m the author, would be happy to hear from other devs whether this way of explaining things makes sense, and what you’d add or change for future posts in the series.

Hope you find it useful.

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[-] DickFiasco@sh.itjust.works 32 points 8 months ago

Thank you, this is a great explanation. I look forward to the rest of this series.

[-] zknd@lemmy.world 10 points 8 months ago

Thank you for the feedback.

[-] ambitiousslab@lemmy.ml 12 points 8 months ago* (last edited 8 months ago)

It's a very good explanation. I like that it is short and hands on. For me, it is pitched at the right level and the practical style keeps it very grounded.

what you’d add or change for future posts in the series

I wouldn't change anything to do with the content! Speaking personally, I'm a fan of full text RSS feeds, so I'd love one on this blog if that's an option :)

[-] AWizard_ATrueStar@lemmy.world 7 points 8 months ago

I think there is one. All the way at the bottom of the page I see a link for RSS and I was able to add it to my RSS reader. It looks like everything is there unless I am missing something.

[-] ambitiousslab@lemmy.ml 3 points 8 months ago

I'm not sure if your RSS reader is getting the content through some special way. The feed itself only has the first two paragraphs:

<item>
  <title>The Linux kernel is just a program</title>
  <link>https://serversfor.dev/linux-inside-out/the-linux-kernel-is-just-a-program/</link>
  <guid isPermaLink="true">https://serversfor.dev/linux-inside-out/the-linux-kernel-is-just-a-program/</guid>
  <description>Most books and courses introduce Linux through shell commands, leaving the kernel as a mysterious black box doing magic behind the scenes. In this post, we will run some experiments to demystify it: the Linux kernel is just a binary that you can build and run.</description>
  <pubDate>Mon, 01 Dec 2025 00:00:00 GMT</pubDate>
</item>
[-] zknd@lemmy.world 4 points 8 months ago

Turned out it is not so simple to add the full content of the post to the RSS feed with Astro's RSS plugin, but trying to find some workaround.

[-] ambitiousslab@lemmy.ml 3 points 8 months ago

Ok, no pressure anyway! Thanks for looking into it :)

[-] zknd@lemmy.world 4 points 8 months ago

Thank you for the feedback.

Sure, I will look into the RSS plugin config. :)

[-] calliope@retrolemmy.com 9 points 8 months ago

This is very cool, thanks for sharing!

I did a similar exercise a decade ago with HTTP and it was fun and eye-opening.

[-] gsx@discuss.tchncs.de 7 points 8 months ago

Nice article. Waiting for the upcoming parts.

Blinry did something similar not to lomg ago, maybe it's interesting for you, too: https://blinry.org/tiny-linux/

[-] sfxrlz@lemmy.dbzer0.com 5 points 8 months ago

This looks really interesting. I’ll have a look when I get home.

[-] lascapi@jlai.lu 4 points 8 months ago

That looks simple when someone (you) say it simply.

Thank you for that. 😌

[-] harsh3466@lemmy.ml 3 points 8 months ago

This sounds awesome. I'm going to read this tomorrow when I can give it my full attention.

[-] LainTrain@lemmy.dbzer0.com 2 points 8 months ago

That's so cool! Thanks for sharing it!

[-] thatradomguy@lemmy.world -2 points 8 months ago

AI is just a program.

this post was submitted on 05 Dec 2025
213 points (98.6% liked)

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