MinimalRTOS-Kernel

A minimal RTOS kernel implemented from scratch on ARM Cortex-M to understand core scheduling and kernel concepts beyond using existing RTOS libraries.

Overview

This project demonstrates the internal working of a small RTOS kernel, including task management and scheduling decisions.
The implementation is intentionally minimal and educational, focusing on clarity and correctness rather than feature completeness.

Features

• Cooperative scheduling
• Round-Robin scheduling using SysTick time slicing
• Compile-time scheduler selection using macros
• Basic task creation and management
• Demonstration using multiple tasks

Scheduler Selection

The scheduler is selected at compile time via configuration macros, allowing easy comparison between different scheduling strategies without changing application code.

File Structure

• main.c – Application entry point and task definitions
• osKernel.c – Core kernel and scheduler logic
• rtos_config.h – RTOS configuration and scheduler selection
• timebase.c – Time base support (optional/future use)

Target Platform

• ARM Cortex-M microcontrollers
  (Tested on STM32 / similar MCUs)

Motivation

This project was built to gain a deeper understanding of RTOS internals, such as scheduling behavior, time slicing, and kernel design, rather than relying solely on existing RTOS implementations like FreeRTOS.

Future Work

• Priority-based preemptive scheduler
• Improved task state management
• Architecture-specific port separation