L-1.0 Introduction : What is RTOS ?

A real-time operating system (RTOS) is an OS that guarantees real-time applications a certain capability within a specified deadline. RTOSes are designed for critical systems and for devices like microcontrollers that are timing-specific. RTOS processing time requirements are measured in milliseconds.

There are three types of RTOS: 1) Hard RTOS, 2) Soft RTOS, and 3) Firm RTOS. Important components of RTOS are Scheduler, Communication Mechanism, Critical Region Mechanisms, Timing Services, Power Management, and Memory Management. Performance is the most important factor in RTOS.1