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.
  • LeFantome@programming.dev
    51·
    23 hours ago

    Well, the kernel is not “just a program” in that it is not like the other programs on your system. If it was, you would “just” run it in your shell. The kernel cannot run this way of course because it is not a user mode program.

    That said, if course the kernel is a program in the sense that it is a set of machine instructions that make the hardware do what you want.

    And the kernel is designed to talk to hardware and other programs—to be the bridge between the two. It is not something an end-user interacts with directly.

    • GlowHuddy@lemmy.world
      3·
      19 hours ago

      Well, the kernel is not “just a program” in that it is not like the other programs on your system. If it was, you would “just” run it in your shell. The kernel cannot run this way of course because it is not a user mode program.

      Actually…

      • LeFantome@programming.dev
        1·
        14 minutes ago

        Point taken but….

        UML requires:

        1 - extensive support from the host kernel above and beyond what is required to execute for regular programs

        2 - the guest kernel to be specially compiled to be a UML guest

        In other words, even though UML allows a guest Linux kernel to execute as a process on a host Linux kernel, that Linux kernel is not “just a program” like every other user mode application is.

  • davel [he/him]@lemmy.mlEnglish
    461·
    2 days ago

    It’s a program certainly, but “just a program” is a bit misleading because it places it on the same footing as Doom or cat or an Arduino project. Linux is a ring 0 program, which processors give unique treatment.

  • lemmyseizethemeans@lemmygrad.ml
    7·
    2 days ago

    Thanks op this is a great article. Having compiled kernels since 2.4 or thenabouts, it’s a great topic and I never really thought of it as just another program. Neat stuff!

  • dubyakay@lemmy.ca
    3·
    2 days ago

    On my arch install, all I have is vmlinuz-linux under /boot. How come there’s no further information appended like in the article?

    • atzanteol@sh.itjust.worksEnglish
      6·
      2 days ago

      Different distros vary a bit here, and it will differ if you’re on a system using efi.

      Sometimes /boot isn’t mounted by default (it’s not needed unless you’re updating a kernel). You may be seeing a symlink or placeholder there.

      If you’re using efi there will probably be /boot/EFI or something where your kernel is stored.

    • trolololol@lemmy.world
      1·
      22 hours ago

      I liked both this and the following article.

      Pretty cool seeing everything it takes to have a minimalist Linux to boot, and I finally saw how to get started with strace that I’ve been postponing for like half a year.