In this chapter, we examine one of the most important and widely used categories of operating systems: embedded operating systems. The embedded system environment places unique and demanding requirements on the OS and calls for design strategies quite different than that found in ordinary operating systems. | Chapter 13 Embedded Systems Embedded Systems Characteristics of Embedded Operating Systems Embedded System A combination of hardware and software designed to perform a dedicated function Often, embedded systems are part of a larger system or product, ., antilock braking system in a car Embedded systems are tightly coupled to their environment imposes real-time constraints by the need to interact with the environment Examples of Embedded Devices Differences from typical computer A variety of interfaces enable the system to measure, manipulate, and interact with the external environment human interface may be as simple as a flashing light or as complicated as real-time robotic vision Use of a diagnostic port for diagnosing the system Use of special purpose hardware to increase performance or safety Fixed-function or application-specific software Roadmap Embedded Systems Characteristics of Embedded Operating Systems Characteristics of Embedded OS Using a . | Chapter 13 Embedded Systems Embedded Systems Characteristics of Embedded Operating Systems Embedded System A combination of hardware and software designed to perform a dedicated function Often, embedded systems are part of a larger system or product, ., antilock braking system in a car Embedded systems are tightly coupled to their environment imposes real-time constraints by the need to interact with the environment Examples of Embedded Devices Differences from typical computer A variety of interfaces enable the system to measure, manipulate, and interact with the external environment human interface may be as simple as a flashing light or as complicated as real-time robotic vision Use of a diagnostic port for diagnosing the system Use of special purpose hardware to increase performance or safety Fixed-function or application-specific software Roadmap Embedded Systems Characteristics of Embedded Operating Systems Characteristics of Embedded OS Using a general-purpose OS for an embedded system may not be possible constraint of memory space constraint of power consumption real-time requirements Special-purpose OS designed for the embedded system environment is commonly used. Characteristics of Embedded OS Real-time operation correctness of computation depends, in part, on the time at which result is delivered Reactive operation needs to consider worst-case conditions in execution in order to respond to external events that do not occur at predictable intervals Characteristics of Embedded OS Configurability supports flexible configuration so that only the functionality needed for a specific application and hardware suite is provided ., allows to select only the necessary OS modules to load I/O device flexibility handles devices by using special tasks instead of integrating their drives into the OS kernel Characteristics of Embedded OS Streamlined protection mechanisms requires limited protection because tested software can be assumed
