How to Learn and Develop a Simple Real-Time Operating System: A Guide for Beginners
Real-time operating systems (RTOS) are software platforms that manage the execution of tasks and processes in embedded systems that have strict timing constraints. RTOS are widely used in applications such as robotics, aerospace, automotive, industrial control, and medical devices. However, many embedded engineers are not comfortable with using RTOS, either because they lack the theoretical background or the practical skills to develop one.
This article aims to provide a comprehensive introduction to RTOS concepts and implementation, based on the book Simple Real-time Operating System: A Kernel Inside View for a Beginner by Chowdary Venkateswara Penumuchu[^1^]. The book covers the basic principles of RTOS design and development, and illustrates them with a simple RTOS kernel named SROS (Simple Real-time Operating System). The book also provides code examples and exercises for readers to practice and learn by doing.
What is an RTOS
An RTOS is a software platform that manages the execution of tasks and processes in an embedded system that has strict timing constraints. An RTOS provides services such as task scheduling, inter-task communication, synchronization, memory management, interrupt handling, and device drivers. An RTOS also ensures that the system meets its real-time requirements, such as deadlines, responsiveness, predictability, and reliability.
An RTOS differs from a general-purpose operating system (GPOS) in several ways. First, an RTOS is designed for specific hardware platforms and applications, while a GPOS is designed for general-purpose computing. Second, an RTOS has a smaller footprint and lower overhead than a GPOS, as it only includes the essential features and services for real-time applications. Third, an RTOS has a different scheduling policy than a GPOS, as it prioritizes tasks based on their urgency and importance rather than their fairness or resource utilization.
Why use an RTOS
Using an RTOS can offer several benefits for embedded systems development. Some of these benefits are:
Simplifying the application logic by abstracting the low-level details of hardware and software interactions.
Improving the modularity and reusability of code by separating tasks into independent units that can communicate through well-defined interfaces.
Enhancing the performance and reliability of the system by ensuring that critical tasks meet their deadlines and avoid interference from other tasks.
Facilitating the testing and debugging of the system by providing tools and mechanisms for monitoring and controlling the behavior of tasks.
Enabling the portability and scalability of the system by supporting different hardware platforms and configurations.
How to learn and develop an RTOS
The best way to learn and develop an RTOS is to follow a hands-on approach that combines theory and practice. The book Simple Real-time Operating System: A Kernel Inside View for a Beginner by Chowdary Venkateswara Penumuchu[^1^] provides such an approach by explaining all the basic concepts of RTOS in detail and implementing them in a simple RTOS kernel named SROS. The book also provides code examples and exercises for readers to practice and learn by doing.
The book covers the following topics:
The architecture and components of an RTOS.
The task model and task states of an RTOS.
The task scheduling algorithms and policies of an RTOS.
The inter-task communication mechanisms of an RTOS, such as message queues, semaphores, mutexes, event flags, mailboxes, pipes, signals, etc.
The synchronization techniques of an RTOS, such as priority inheritance, priority ceiling, etc.
The memory management schemes of an RTOS, such as static allocation, dynamic allocation, memory pools, etc.
The interrupt handling mechanisms of an RTOS, such as interrupt service routines (ISR), deferred interrupt processing (DIP), etc.
The device driver development for an RTOS.
The testing and debugging tools and methods for an RTOS.
The book also provides a step-by-step guide on how to a474f39169