RK0 - The Real-Time Kernel '0'

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About

RK0 is a lean, feature-rich, highly deterministic Real-Time Kernel for deeply embedded solutions.

Supported Architectures: ARMv6M (Cortex-M0/0+) and ARMv7M (Cortex-M3/4/7).

Documentation

• The RK0 Docbook provides a comprehensive system description

  • PDF Docbook
  • HTML Docbook

• RK0 Wiki details application structuring, QEMU setup, reference projects for download (Nucleo boards)

• RK0 Blog provides some quick complementary reads.

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RK0 Main Features (V0.9.11-dev)

• O(1) Scheduler: priority preemptive (RMS)

• Synch Pack:

  • Semaphores (Counting/Binary)
  • Mutexes with fully transitive Priority Inheritance
  • Conditional Critical Regions (Condition Variable/Monitor-like constructions)
  • Task Event Registers

• Priority-aware message-passing

  • Message Queues (Mailboxes) for general asynchronous message-passing
  • Ports for client-server synchronous RPC, message-driven priority inheritance

• Most-Recent Message Protocol

  • Asynchronous, Lock-Free, purpose-built for Real-time Control Loops

• High-Precision Timers:

  • Minimal Tick Handling overhead for Bounded Waiting, Phase-locked Periodic Releases and Callout Timers.

• Memory Partition:

  • Well-proven, deterministic memory allocator suitable for real-time systems.

• Suits both procedural/shared-memory and message-passing paradigms

• Highly Modular with clean and consistent API.

• (And that wicked cool mascot)

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Quick Start (QEMU)

Prerequisites:

• ARM GNU Toolchain (arm-none-eabi-gcc, arm-none-eabi-gdb / gdb-multiarch (Debian))
• QEMU for ARM (qemu-system-arm)

Build and run the RK0 demo on QEMU:

git clone https://github.com/antoniogiacomelli/RK0.git
cd RK0
make arch=<armv6/7m> qemu

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Code Quality

RK0 source code compiles cleanly with the following GCC flags:

-Wall -Wextra -Wsign-compare -Wsign-conversion -pedantic

Static Analysis (Cppcheck) is clean with no warnings, errors, or style issues.

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Dependencies

• ARM-GCC, CMSIS-GCC

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Copyright (C) 2026 Antonio Giacomelli | All Rights Reserved | www.kernel0.org | 📫