LibreRTOS

Copyright (c) 2016-2023 Djones A. Boni - MIT License

LibreRTOS is a portable Single-Stack Real-Time Operating System.

The main objective of LibreRTOS is to run in microcontrollers.

Features:

• Preemptive and cooperative kernel modes.
• Tasks and timers with priorities.
• Synchronization with queues, semaphores and mutexes.

Design goals:

• Portability:
  • Strictly standard C (no compiler extensions), and
  • Minimal assembly required (only 4 macros to manage interrupts).
• Real-Time: all operations that disable interrupts take constant time O(1).
• Single-Stack: all tasks share the same stack, allowing a large number of tasks to be created on RAM constrained projects.
  • The tasks must run to completion and must hold state in static memory.
• Static allocation: no use of malloc/free and such.

Notes:

• Interrupts that use LibreRTOS API must lock the scheduler at the beginning and unlock it before returning.

Using LibreRTOS in Your Project

1. Get the code:
   • Clone this project using Git, or
   • Download LibreRTOS as a zip file and extract it.
2. Copy src/librertos.c and include/librertos.h to your project
3. Add #include "librertos.h" to your source files and use LibreRTOS
4. Create a port file librertos_port.h for your hardware (see the examples)
5. Create a project file librertos_proj.h for your project (see the examples)
6. Initialize and use LibreRTOS in your project (see more in the documentation)

Examples and Documentation

• The user documentation is available in the doc/ directory.
• Examples can be found in the examples/ directory
• Implementation details are documented in the code.