# littlekernel/lk

LK embedded kernel

Repository: https://github.com/littlekernel/lk
Canonical: https://ross.abutalabs.com/products/lk
Language: C
License: MIT
License Family: permissive
Topics: operating-system, rtos
Last push: 2026-08-26T17:26:56+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 5363, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3667, forks 766 (observed 2026-08-28T04:08:13.421167+00:00)

## What it is
LK (Little Kernel) is a small SMP-aware embedded kernel written in C, portable to many 32- and 64-bit CPU architectures including ARM, RISC-V, x86, MIPS, and 68000. It features a fully re-entrant preemptive multithreaded kernel and is widely used in embedded projects, notably as the bootloader for many Android phones.

## Use cases
- build a custom RTOS for a microcontroller
- write an embedded bootloader for ARM or RISC-V hardware
- run a small preemptive multithreaded kernel on bare metal
- port a lightweight kernel to a new 32-bit or 64-bit architecture
- develop firmware for Cortex-M or Cortex-A cores
- use a minimal kernel as a base for an Android device bootloader

## When to choose
- you need a small, portable, SMP-capable embedded kernel with permissive MIT licensing
- you are targeting ARM, RISC-V, x86, MIPS, or 68000 embedded platforms
- you want a proven codebase used in production bootloaders

## When to avoid
- you need a full POSIX-compliant OS with rich userspace
- you want a Linux-based system with drivers and package ecosystems
- you need hard real-time guarantees certified for safety-critical use

## Facets
- artifact type: library
- maturity: active
- function: embedded, concurrency
- domain: embedded-systems, operating-systems, hardware
- platform: embedded, c
- tags: rtos, kernel, bootloader, microcontroller, smp, bare-metal, operating-system, arm, riscv, x86

## Member repositories
- littlekernel/lk (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:13.421167+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:31:31.680939+00:00, confidence not recorded.
  - readme: https://github.com/littlekernel/lk (fetched 2026-08-28T04:08:13.421167+00:00, sha 08a7b74d3cae)
- Data as of 2026-08-30T08:39:29.467469+00:00.