161204 Mastering The Free RTOS Real Time Kernel A Hands On Tutorial Guide

• Contents
• List of Figures
• List of Code Listings
• List of Tables
• List of Notation
• Preface
  • Multitasking in Small Embedded Systems
    • About FreeRTOS
    • Value Proposition
    • A Note About Terminology
    • Why Use a Real-time Kernel?
    • FreeRTOS Features
    • Licensing, and The FreeRTOS, OpenRTOS, and SafeRTOS Family
  • Included Source Files and Projects
    • Obtaining the Examples that Accompany this Book
• SECTION 1.
• Chapter 1 The FreeRTOS Distribution
  • 1.1 Chapter Introduction and Scope
    • Scope
  • 1.2 Understanding the FreeRTOS Distribution
    • Definition: FreeRTOS Port
    • Building FreeRTOS
    • FreeRTOSConfig.h
    • The Official FreeRTOS Distribution
    • The Top Directories in the FreeRTOS Distribution
    • FreeRTOS Source Files Common to All Ports
    • FreeRTOS Source Files Specific to a Port
    • Header Files
  • 1.3 Demo Applications
  • 1.4 Creating a FreeRTOS Project
    • Adapting One of the Supplied Demo Projects
    • Creating a New Project from Scratch
  • 1.5 Data Types and Coding Style Guide
    • Data Types
    • Variable Names
    • Function Names
    • Formatting
    • Macro Names
    • Rationale for Excessive Type Casting
• Chapter 2 Heap Memory Management
  • 2.1 Chapter Introduction and Scope
    • Prerequisites
    • Dynamic Memory Allocation and its Relevance to FreeRTOS
    • Options for Dynamic Memory Allocation
    • Scope
  • 2.2 Example Memory Allocation Schemes
    • From FreeRTOS V9.0.0 FreeRTOS applications can be completely statically allocated, removing the need to include a heap memory manager
    • Heap_1
    • Heap_2
    • Heap_3
    • Heap_4
    • Setting a Start Address for the Array Used By Heap_4
    • Heap_5
    • The vPortDefineHeapRegions() API Function
  • 2.3 Heap Related Utility Functions
    • The xPortGetFreeHeapSize() API Function
    • The xPortGetMinimumEverFreeHeapSize() API Function
    • Malloc Failed Hook Functions
• Chapter 3 Task Management
  • 3.1 Chapter Introduction and Scope
    • Scope
  • 3.2 Task Functions
  • 3.3 Top Level Task States
  • 3.4 Creating Tasks
    • The xTaskCreate() API Function
    • Example 1. Creating tasks
    • Example 2. Using the task parameter
  • 3.5 Task Priorities
  • 3.6 Time Measurement and the Tick Interrupt
    • Example 3. Experimenting with priorities
  • 3.7 Expanding the ‘Not Running’ State
    • The Blocked State
    • The Suspended State
    • The Ready State
    • Completing the State Transition Diagram
    • Example 4. Using the Blocked state to create a delay
    • The vTaskDelayUntil() API Function
    • Example 5. Converting the example tasks to use vTaskDelayUntil()
    • Example 6. Combining blocking and non-blocking tasks
  • 3.8 The Idle Task and the Idle Task Hook
    • Idle Task Hook Functions
    • Limitations on the Implementation of Idle Task Hook Functions
    • Example 7. Defining an idle task hook function
  • 3.9 Changing the Priority of a Task
    • The vTaskPrioritySet() API Function
    • The uxTaskPriorityGet() API Function
    • Example 8. Changing task priorities
  • 3.10 Deleting a Task
    • The vTaskDelete() API Function
    • Example 9. Deleting tasks
  • 3.11 Thread Local Storage
  • 3.12 Scheduling Algorithms
    • A Recap of Task States and Events
    • Configuring the Scheduling Algorithm
    • Prioritized Pre-emptive Scheduling with Time Slicing
    • Prioritized Pre-emptive Scheduling (without Time Slicing)
    • Co-operative Scheduling
• Chapter 4 Queue Management
  • 4.1 Chapter Introduction and Scope
    • Scope
  • 4.2 Characteristics of a Queue
    • Data Storage
    • Access by Multiple Tasks
    • Blocking on Queue Reads
    • Blocking on Queue Writes
    • Blocking on Multiple Queues
  • 4.3 Using a Queue
    • The xQueueCreate() API Function
    • The xQueueSendToBack() and xQueueSendToFront() API Functions
    • The xQueueReceive() API Function
    • The uxQueueMessagesWaiting() API Function
    • Example 10. Blocking when receiving from a queue
  • 4.4 Receiving Data From Multiple Sources
    • Example 11. Blocking when sending to a queue, and sending structures on a queue
  • 4.5 Working with Large or Variable Sized Data
    • Queuing Pointers
    • Using a Queue to Send Different Types and Lengths of Data
  • 4.6 Receiving From Multiple Queues
    • Queue Sets
    • The xQueueCreateSet() API Function
    • The xQueueAddToSet() API Function
    • The xQueueSelectFromSet() API Function
    • Example 12. Using a Queue Set
    • More Realistic Queue Set Use Cases
  • 4.7 Using a Queue to Create a Mailbox
    • The xQueueOverwrite() API Function
    • The xQueuePeek() API Function
• Chapter 5 Software Timer Management
  • 5.1 Chapter Introduction and Scope
    • Scope
  • 5.2 Software Timer Callback Functions
  • 5.3 Attributes and States of a Software Timer
    • Period of a Software Timer
    • One-shot and Auto-reload Timers
    • Software Timer States
  • 5.4 The Context of a Software Timer
    • The RTOS Daemon (Timer Service) Task
    • The Timer Command Queue
    • Daemon Task Scheduling
  • 5.5 Creating and Starting a Software Timer
    • The xTimerCreate() API Function
    • The xTimerStart() API Function
    • Example 13. Creating one-shot and auto-reload timers
  • 5.6 The Timer ID
    • The vTimerSetTimerID() API Function
    • The pvTimerGetTimerID() API Function
    • Example 14. Using the callback function parameter and the software timer ID
  • 5.7 Changing the Period of a Timer
    • The xTimerChangePeriod() API Function
  • 5.8 Resetting a Software Timer
    • The xTimerReset() API Function
    • Example 15. Resetting a software timer
• Chapter 6 Interrupt Management
  • 6.1 Chapter Introduction and Scope
    • Events
    • Scope
  • 6.2 Using the FreeRTOS API from an ISR
    • The Interrupt Safe API
    • The Benefits of Using a Separate Interrupt Safe API
    • The Disadvantages of Using a Separate Interrupt Safe API
    • The xHigherPriorityTaskWoken Parameter
    • The portYIELD_FROM_ISR() and portEND_SWITCHING_ISR() Macros
  • 6.3 Deferred Interrupt Processing
  • 6.4 Binary Semaphores Used for Synchronization
    • The xSemaphoreCreateBinary() API Function
    • The xSemaphoreTake() API Function
    • The xSemaphoreGiveFromISR() API Function
    • Example 16. Using a binary semaphore to synchronize a task with an interrupt
    • Improving the Implementation of the Task Used in Example 16
  • 6.5 Counting Semaphores
    • The xSemaphoreCreateCounting() API Function
    • Example 17. Using a counting semaphore to synchronize a task with an interrupt
  • 6.6 Deferring Work to the RTOS Daemon Task
    • The xTimerPendFunctionCallFromISR() API Function
    • Example 18. Centralized deferred interrupt processing
  • 6.7 Using Queues within an Interrupt Service Routine
    • The xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() API Functions
    • Considerations When Using a Queue From an ISR
    • Example 19. Sending and receiving on a queue from within an interrupt
  • 6.8 Interrupt Nesting
    • A Note to ARM Cortex-M and ARM GIC Users
• Chapter 7 Resource Management
  • 7.1 Chapter Introduction and Scope
    • Mutual Exclusion
    • Scope
  • 7.2 Critical Sections and Suspending the Scheduler
    • Basic Critical Sections
    • Suspending (or Locking) the Scheduler
    • The vTaskSuspendAll() API Function
    • The xTaskResumeAll() API Function
  • 7.3 Mutexes (and Binary Semaphores)
    • The xSemaphoreCreateMutex() API Function
    • Example 20. Rewriting vPrintString() to use a semaphore
    • Priority Inversion
    • Priority Inheritance
    • Deadlock (or Deadly Embrace)
    • Recursive Mutexes
    • Mutexes and Task Scheduling
  • 7.4 Gatekeeper Tasks
    • Example 21. Re-writing vPrintString() to use a gatekeeper task
• Chapter 8 Event Groups
  • 8.1 Chapter Introduction and Scope
    • Scope
  • 8.2 Characteristics of an Event Group
    • Event Groups, Event Flags and Event Bits
    • More About the EventBits_t Data Type
    • Access by Multiple Tasks
    • A Practical Example of Using an Event Group
  • 8.3 Event Management Using Event Groups
    • The xEventGroupCreate() API Function
    • The xEventGroupSetBits() API Function
    • The xEventGroupSetBitsFromISR() API Function
    • The xEventGroupWaitBits() API Function
    • Example 22. Experimenting with event groups
  • 8.4 Task Synchronization Using an Event Group
    • The xEventGroupSync() API Function
    • Example 23. Synchronizing tasks
• Chapter 9 Task Notifications
  • 9.1 Chapter Introduction and Scope
    • Communicating Through Intermediary Objects
    • Task Notifications—Direct to Task Communication
    • Scope
  • 9.2 Task Notifications; Benefits and Limitations
    • Performance Benefits of Task Notifications
    • RAM Footprint Benefits of Task Notifications
    • Limitations of Task Notifications
  • 9.3 Using Task Notifications
    • Task Notification API Options
    • The xTaskNotifyGive() API Function
    • The vTaskNotifyGiveFromISR() API Function
    • The ulTaskNotifyTake() API Function
    • Example 24. Using a task notification in place of a semaphore, method 1
    • Example 25. Using a task notification in place of a semaphore, method 2
    • The xTaskNotify() and xTaskNotifyFromISR() API Functions
    • The xTaskNotifyWait() API Function
    • Task Notifications Used in Peripheral Device Drivers: UART Example
    • Task Notifications Used in Peripheral Device Drivers: ADC Example
    • Task Notifications Used Directly Within an Application
• Chapter 10 Low Power Support
• Chapter 11 Developer Support
  • 11.1 Chapter Introduction and Scope
  • 11.2 configASSERT()
    • Example configASSERT() definitions
  • 11.3 FreeRTOS+Trace
  • 11.4 Debug Related Hook (Callback) Functions
    • Malloc failed hook
  • 11.5 Viewing Run-time and Task State Information
    • Task Run-Time Statistics
    • The Run-Time Statistics Clock
    • Configuring an Application to Collect Run-Time Statistics
    • The uxTaskGetSystemState() API Function
    • The vTaskList() Helper Function
    • The vTaskGetRunTimeStats() Helper Function
    • Generating and Displaying Run-Time Statistics, a Worked Example
  • 11.6 Trace Hook Macros
    • Available Trace Hook Macros
    • Defining Trace Hook Macros
    • FreeRTOS Aware Debugger Plug-ins
• Chapter 12 Trouble Shooting
  • 12.1 Chapter Introduction and Scope
  • 12.2 Interrupt Priorities
  • 12.3 Stack Overflow
    • The uxTaskGetStackHighWaterMark() API Function
    • Run Time Stack Checking—Overview
    • Run Time Stack Checking—Method 1
    • Run Time Stack Checking—Method 2
  • 12.4 Inappropriate Use of printf() and sprintf()
    • Printf-stdarg.c
  • 12.5 Other Common Sources of Error
    • Symptom: Adding a simple task to a demo causes the demo to crash
    • Symptom: Using an API function within an interrupt causes the application to crash
    • Symptom: Sometimes the application crashes within an interrupt service routine
    • Symptom: The scheduler crashes when attempting to start the first task
    • Symptom: Interrupts are unexpectedly left disabled, or critical sections do not nest correctly
    • Symptom: The application crashes even before the scheduler is started
    • Symptom: Calling API functions while the scheduler is suspended, or from inside a critical section, causes the application to crash
• INDEX