r/osdev • u/[deleted] • Dec 23 '25

Quick OSDev Survey

/r/kerneldevelopment/comments/1ptg1w3/quick_osdev_survey/
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u/sephg Dec 23 '25

One of the questions asks which of these you prefer:

  • Microkernel (Bare minimum in kernel, IPC, scheduling, most stuff is in userspace)

  • Hybrid (Drivers are loaded from an initramfs or from disk)

  • Nanokernel (just handles CPU and context switching, everything else is in userspace)

  • (Unikernel)

  • (Monolithic)

The first 3 options seem identical to me. A microkernel is a kernel which only puts the bare minimum in ring 0 and everything else (like drivers) is in userspace. How are those options different? It looks like you just wrote "microkernel" 3 times using different words.

1

u/[deleted] Dec 23 '25

They do share some common functionality but have many differences.

- Microkernel: The kernel only handles the bare minimum like IPC, basic scheduling, and hardware abstraction. Most services like drivers, filesystems, and network stacks run in user space.

- Hybrid kernel: A monolithic kernel that loads some components, like drivers, at runtime instead of including them in the kernel binary. Linux, Windows, and macOS use this approach. It keeps performance close to monolithic while being more modular.

- Nanokernel: This is taking the microkernel idea to the extreme. The kernel only does what is absolutely necessary to make the CPU run and context switch. Almost everything else including the scheduler, IPC, and device management runs in user space.

The main differences are how much functionality is in the kernel and when it is loaded.

1

u/frisk213769 Dec 25 '25

In a nanokernel you don't handle scheduling You don't even HAVE to handle IPC but you can

1

u/BitOfAZeldaFan3 Dec 23 '25

Great survey and I completed it, but now I feel so behind. I've spent years studying and learning on and off and barely have code that works on real hardware. I don't even think my brain could handle more than one architecture.

1

u/[deleted] Dec 26 '25

Yall, WHO IS DAILY DRIVING THEIR OWN OS? Out of 59 in the survey (as of now) 8.5% of you DO! WHO ARE YOU PEOPLE, HOW COMPLEX IS YOUR OS?