Ask HN: Examples of Microkernels?

• xv6-riscv

  17 6,144 0.0 C

  Xv6 for RISC-V

  

I'm reading through the MIT xv6 OS handbook and code (here: https://github.com/mit-pdos/xv6-riscv/) and they mention the fact that they created it as a monolithic kernel since most unix systems are monolithic. They then introduce the microkernel concept. Are there microkernel concepts out there (especially code) I can check out? I'm curious to see how userspace processes communicate to kernel processes to execute privileged actions.

• lk

  9 3,065 8.6 C

  LK embedded kernel

  

This is based on little kernel from recollection (noted somewhere in the docs)

https://github.com/littlekernel/lk

• InfluxDB

  www.influxdata.com sponsored

  Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.

  

• rCore

  2 3,326 2.5 Rust

  Rust version of THU uCore OS. Linux compatible.

  

• zCore

  2 1,669 0.0 Rust

  Zircon microkernel reimplemented in Rust.

  

• FreeRTOS-Kernel

  12 2,332 9.4 C

  FreeRTOS kernel files only, submoduled into https://github.com/FreeRTOS/FreeRTOS and various other repos.

  

• qubes-mirage-firewall

  5 201 7.2 OCaml

  A Mirage firewall VM for QubesOS

  

Here's one that is "production" ready: the Mirage-Firewall microkernel running on Qubes OS.[0]

[0] : https://github.com/mirage/qubes-mirage-firewall

• composite

  1 181 7.1 C

  A component-based OS (by gwsystems)

  

• WorkOS

  workos.com sponsored

  The modern identity platform for B2B SaaS. The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.

  

• xnu

  47 1,353 3.5 C
  

• dyld

  32 531 4.0 C++
  

• hubris

  33 2,790 9.4 Rust

  A lightweight, memory-protected, message-passing kernel for deeply embedded systems.

  

Hubris is a microkernel-ish OS for embedded systems, and has a bunch of documentation about its design:

https://hubris.oxide.computer/reference/

It's all open-source on Github:

https://github.com/oxidecomputer/hubris

(I work at Oxide, mostly using Hubris)

• unikraft

  2 18 2.4 C

  FlexOS is a Unikraft-based OS allowing users to easily specialize the safety and isolation strategy at compilation time. (by project-flexos)

  

It seemed to be in a similar space to Genode when I had a brief look. Is it clear how it compares?

A system that claims to allow you to configure it in microkernel and other modes might be interesting for comparison of the approaches, but I've only noticed it via a local connexion: https://project-flexos.github.io/

• Atmosphere

  418 13,773 8.7 C++

  Atmosphère is a work-in-progress customized firmware for the Nintendo Switch.

  

The Nintendo Switch runs a microkernel called "Horizon". It has been fully reverse-engineered, and a 1:1 open-source reimplementation exists: https://github.com/Atmosphere-NX/Atmosphere/tree/master/meso...

• darwin-xnu

  186 10,694 0.0 C

  Discontinued Legacy mirror of Darwin Kernel. Replaced by https://github.com/apple-oss-distributions/xnu

  

And the original basis for the NeXTStep -> OpenStep -> OS X -> iOS / MacOS line. Source for XNU, the current incarnation of Apple's microkernel is available as part of the Darwin stuff: https://github.com/apple/darwin-xnu

Suggest a related project