Real-Time Systems Development with RTEMS and Multicore Processors

Description

The proliferation of multicore processors in the embedded market for Internet-of-Things (IoT) and Cyber-Physical Systems (CPS) makes developing real-time embedded applications increasingly difficult. What is the underlying theory that makes multicore real-time possible? How does theory influence application design? When is a real-time operating system (RTOS) useful? What RTOS features do applications need? How does a mature RTOS help manage the complexity of multicore hardware? Real-Time Systems Development with RTEMS and Multicore Processors answers these questions and more with exemplar Real-Time Executive for Multiprocessor Systems (RTEMS) RTOS to provide concrete advice and examples for constructing useful, feature-rich applications. RTEMS is free, open-source software that supports multi-processor systems for over a dozen CPU architectures and over 150 specific system boards in applications spanning the range of IoT and CPS domains such as satellites, particle accelerators, robots, racing motorcycles, building controls, medical devices, and more. The focus of this book is on enabling real-time embedded software engineering while providing sufficient theoretical foundations and hardware background to understand the rationale for key decisions in RTOS and application design and implementation. The topics covered in this book include: Cross-compilation for embedded systems development Concurrent programming models used in real-time embedded software Real-time scheduling theory and algorithms used in wide practice Usage and comparison of two application programmer interfaces (APIs) in real-time embedded software: POSIX and the RTEMS Classic APIs Design and implementation in RTEMS of commonly found RTOS features for schedulers, task management, time-keeping, inter-task synchronization, inter-task communication, and networking The challenges introduced by multicore hardware, advances in multicore real-time theory, and software engineering multicore real-time systems with RTEMS All the authors of this book are experts in the academic field of real-time embedded systems. Two of the authors are primary open-source maintainers of the RTEMS software project. Preface The Authors Chapter 1: Introduction PART 1: Operating System Basics Chapter 2: Cross-Compilation Toolchain 2.1 From Source Code to the Executable Image 2.1.1. The Compiler Driver 2.1.2 The Preprocessor 2.1.3 The Linker 2.2 Linker Scripts 2.2.1 Input and Output Sequences 2.2.2 Memory Layout 2.2.3 Linker Section 2.2.4 Section and Memory Maiming 2.3 GNU Make and Makefiles 2.3.1 Explicit Rules 2.3.2 Variables 2.3.3 Pattern Rules and Automatic Variables 2.3.4 Directives and Functions 2.4 Basic Description of RTEMS and its Configuration System 2.4.1 RTEMS Compile-Time Configuration 2.4.2 Applications Compile-Time Configuration 2.5 Summary Chapter 3: Concurrent Programming and Scheduling Algorithms 3.1 Foundations of Concurrent Programming 3.1.1 From Interrupt Handling to Multiprogramming 3.1.2 Cooperating Sequential Processes 3.2 Scheduling Policies Mechanisms and Algorithms 3.2.1 Task Interleaviug and Timing 3.2.2 Task Control Block and Task State Diagain 3.2.3 Real-Time Scheduling Algorithms 3.3 Summary Chapter 4: Scheduling Analysis and Interrupt Handling 4.1 Basics of Real-Time Scheduling Analysis 4.1.1 Utilization-Based Schedulability Tests 4.1.2 Response Time Analysis 4.1.3 Task Interactions and Self-Suspension 4.2 Practical Considerations on Interrupt Handling 4.2.1 Exception Handling in The Cortex-M Processor 4.2.2 Exception Priorities and Entry/Exit Sequence 4.2.3 RTEMS Context Switch and Exception Handling 4.2.4 Interrupts in Schedulability Analysis 4.3 Summary PART II Task Management and Timekeeping Chapter 5: Task Management and Timekeeping, Classic API 5.1 Task Management Basics 5.2 Scheduler Manager and Single-Core Scheduling Algorithms 5.3 RTEMS Classic and POSIX API 5.4 Task Management 5.5 The Rate Monotonic Manager 5.6 Timekeeping: Clocks and Timers 5.7 Preemption and Interrupt Management 5.8 Summary Chapter 6: Task Management and Timekeeping, POSIX API 6 1 Attribute Objects 6.2 Thread Creation and Termination 6.3 Thread Scheduling 6.4 Forced Thread Termination (Cancellation) 6.5 Signal Handling 6.6 Timekeeping 6.7 Summary PART III: Inter-Task Synchronization and Communication Chapter 7: Inter-Task Synchronization and Communication (IPC) Kiser] On Shared Memory 7.1 Race Conditions and Mutual Exclusion 7.1.1 An Example of Race Condition 7.1.2 Critical Regions 7.1.3 Lock-Based Mutual Exclusion 7.1.4 Correctness Conditions 7.2 Semaphores 7.2.1 Definition and Properties 7.2.2 Mutual Exclusion Semaphores 7.2.3 Synchronization Semaphores 7.2.4 Producers and Consumers 7.3 Monitors 7.3.1 Definition and Properties 7.3.2 Condition Variables 7.4 RTEMS API for Shared-Memory IPC 7.4.1 Classic API 7.4.2 POSIX API 7.5 Barriers 7.5.1 General Definition 7.5.2 Classic API 7.5.3 POSIX API 7.6 Events 7.7 Summary Chapter 8: IPC Task Execution and Scheduling 8.1 Priority Inversion 8.1.1 Mutual Exclusion and Priority Inversion 8.1.2 The Priority Inheritance Protocol 8.1.3 The Priority Ceiling Protocol 8.2 Deadlock 8.2.1 Definition and Examples of Deadlock 8.2.2 Deadlock in the Producers-Consumers Problems 8.2.3 Deadlock Prevention 8.2.4 Deadlock Avoidance 8.2.5 Deadlock Detection and Recovery 8.3 Summary Chapter 9: IPC Rased on Message Passing 9.1 Unified Synchronization and Data Exchange 9.2 Message Passing Synchronization Models 9.3 Direct and Indirect Naming 9.4 RTEMS API for Message Passing 9.4.1 Classic API 9.4.2 POSIX API 9.3 Summary PART IV Network Communication Chapter 10: Network Communication in RTEMS 10.1 Internal Structure of the RTEMS Networking Code 10.2 Protocol Stack Organisation 10.3 Main Data Structures 10.4 RTEMS Port and Adaptation Layer 10.4.1 Mutual Exclusion and Sleep/Wakeup 10.4.2 Software Interrupts and Network Daemon 10.4.3 Timeout Emulation 10.4.4 Device Driver Organization 10.5 Summary Chapter 11: POSIX Sockets API 11.1 Main Features 11 2 Communication Endpoint Management 11.3 Local Socket Address 11.4 Connection Establishment 11.5 Connectionless Sockets 11.6 Data Transfer 11.7 Socket Options 11.8 Non-Blocking I/O and Synchronous I/O Multiplexing 11.9 Summary PART V Multicores in Real-Time Embedded Systems Chapter 12: Multicores in Embedded Systems 12.1 Motivation 12.2 Multiprocessors and Multicores 12.2.1 Basics of Multicore Architectures 12.2.2 Memory Consistency Models 12.2.3 Cache Coherency 12.2.4 Practical Implementation on ARM Processors 12.2.5 Compiler-Level Instruction Reordering 12.3 Software Challenges Introduced by Multicores 12.3.1 Loss of the Critical Instant Theorem 12.3.2 Dhaffs Effect 12.3.3 Implicit Mutual Exclusion 12.4Sunryna Chapter 13: Multicore Concurrency: Issues and Solutions 13.1 Classes of Multicore Scheduling Algorithms 13.2 Multicore Scheduling Algorithms in RTEMS 13.3 Schedulers Configuration 13.4 Multicore Synchronization Devices 13.4.1 Multiprocessor Resource Sharing Protocol 13.4.2 O(m) Independence-Preserving Protocol 13.5 Lock-Free and Wait-Free Communication 13.5.1 Basic Principles and Definitions 13.5.2 Lock-Free Multi-Word Counter Read 13.5.3 Four-Slot Asynchronous Communication 13.5.4 Universal Construction of Lock-Free Objts 13.6 5pinlocks and Interrupt Handling Synchronization 13.7 Summary References Index