Embedded C Programming with Real Time Linux (i86) — A 5-day Course

An Introduction to C

• Overview
• The C Programming Language
• The C Standards
• The Importance of Standards
• A Simple C Program
• Comments
• Preprocessor Directives
• Functions
• main
• stdio
• Libraries
• printf
• Strings
• Return Values
• Statements
• Review

Introduction to Embedded C Programming

• Overview
• Embedded C and Standard C
• Simple Embedded C Program
• Practical — Compiling the Program
• Differences Between the Standard and Embedded Versions
• Benefits of Using C for Embedded Systems
• C in the Embedded Environment
• C in the Real Time Linux Environment
• Learning Standard C

Variable Types and Constants

• Overview
• Variables
• Basic Variable Types
• Other Variable Types
• Sizes of Data Types
• Declaring Variables
• Declaring Multiple Variables
• Variable Names
• Initialising Variables at Declaration
• Character Constants
• Named Constants
• Boolean Type — Truth Values
• Casting — Type Conversion
• Decimal, Octal, and Hexadecimal Notations

Operators

• Overview
• Operators
• Expressions
• Assignment Operator
• Chaining Assignments
• Arithmetic Operators
• Arithmetic Operators: Division and Remainder
• Example of Remainder
• Increment and Decrement Operators
• Postfix Increment and Decrement
• Relational Operators
• Logical Negation
• Logical Operators
• Short-Circuiting
• Compound Assignment Operators

Flow Control

• Overview
• The if Statement
• Assignment and Equality
• Nested if Statements
• Multi-Way if Statements
• The for Loop
• for Loop Syntax
• The while Loop
• The do-while Loop
• Infinite Loops
• break Statement
• continue Statement
• Conditional Operator
• switch Statement
• switch Caveats
• Shortened Statements
• if Statement Trap
• goto Statement

Functions

• Overview
• The Rôle of Functions
• Function Libraries
• Functions — Syntax
• Return Values
• Function Arguments
• Local Variables
• Scope and Lifetime
• Functions Calling Functions
• Call-by-Value
• Definition and Declaration
• Definition After Use
• Prototypes and Old-Style Declarations
• Variadic Functions

Arrays

• Overview
• Array Basics
• Array Example
• Looping Over an Array
• Array Sizes
• Copying Arrays
• Initialising Arrays
• Strings
• Array Caveats

Evaluating Expressions

• Truth Values
• Precedence
• Associativity
• Operand Evaluation
• Casting - Type Conversion
• Operator Precedence Table
• Operator Precedence Table Continued

Bit Manipulation

• Objectives
• Introduction
• Bit Twiddling Operators
• Bit Shifting
• Portable Bit Manipulation
• Print Bit Representations
• Example — Bit Manipulation
• Summary

Pointers

• Overview
• What is a Pointer?
• Creating a Pointer
• Pointer Types
• Uninitialised Pointers
• Null Pointers
• Pointers as Function Arguments
• Pointers and Arrays
• Pointer Arithmetic
• Using sizeof
• Array/Pointer Equivalence
• Passing Arrays to Functions
• Pointers to Constant Data
• Passing Pointers-to-Const
• Converting Pointers-to-Const

Other Data Types: Structures, Unions, and Enums

• Overview
• Defining Structures
• Using Structures
• Initialising Structure Variables
• Problems with Initialising Structures
• Initialising Arrays of Structures
• Pointers to Structures
• Passing Structures to Functions
• Passing Structure Pointers
• Structures as Data Types
• Enumerations
• Unions
• Discriminating a Union

The Preprocessor and Multiple-File Programs

• Overview
• Standard Headers
• The Preprocessor
• The #define Directive
• Large Programs
• Deciding How to Split a Program
• Sharing Declarations
• Using Header Files
• Writing a Header File
• Conditional Compilation
• Module-Private Functions
• Module-Private Variables
• Function-Private Variables
• Public Module Variables
• When to Use Global Variables

String Handling

• Passing Strings to Functions
• String Handling
• Standard String Functions
• Character Classes
• Available Character Classes
• Letter Case
• Converting a String to a Number
• Converting a Number to a String
• String Input

Real-Time - C Techniques for Dealing with Time

• What is Real-Time?
• Characteristics of Real-Time Applications
• Synchronising I/O with CPU Via Polling
• Synchronising I/O with CPU Via Interrupts
• Interrupts Capabilities of the 16f877 Pic
• Handling Interrupts with C2C
• Interrupts in Real Time Linux
• Generating Delays Via Software
• C Delay Loops
• Generating Delays Via Hardware
• Generating Delays in RTOS
• Example Flash Led Using Timer with Interrupt
• Introducing Multi-Tasking
• Real-Time Operating Systems
• RTLinux Kernel
• Scheduling Algorithms

Tasks, Threads, POSIX Pthreads

• Basics
• Why Tasks?
• Multitasking Example
• Our Terminology
• Processes and Threads Analogy
• Synchronisation, Scheduling and Races
• Thread Basics
• Creating Posix Pthreads
• Creating Threads Example
• Example of Multiple Threads
• Shared Data Problems
• Race Conditions
• Dealing with Critical Sections
• Example of Unprotected Critical Section
• Protecting Critical Sections
• Drawbacks to Mutexes
• Using Condition Variables
• Operations on Condition Variables
• Semaphores
• Spinlocks
• Debugging Multithreaded Programs
• Thread-Safe Functions
• Deadlocks
• Priority Inversion

Self-Referential and Dynamic Data Structures

• Objectives
• Common Data Structures
• Circular Buffers
• Race Conditions
• Singly Linked List
• Data Allocation
• Using malloc and free
• Heap allocation example
• Details of malloc and free
• Supporting Functions
• Doubly Linked Lists

Developing on Real Time Linux

• Real Time Linux Environment
• Typical RTOS Features
• Core RTOS Facilities
• RTLinux
• Architecture of RTLinux Application
• Linux Module Example
• Compiling and Running Modules
• Tiers of Services
• Creating a RTLinux Thread
• Simple Parallel Port Manipulation
• Requesting IO Ports
• Measuring Time
• Elapsed Time in RTLinux

Interprocess Communication in Real Time Linux

• Basics of IPC
• FIFOs
• Shared Memory in RTLinux
• Allocating Shared Memory
• User-Level Shared Memory
• Shared Memory Thread
• Shared Memory Module
• IPC Practical
• Servo Control Example
• Servo Controlled Via IPC
• Software Interrupts
• Software Interrupt API
• Real (Hard) Interrupts
• Hard Interrupt Example

Linux Device Drivers

• Linux Device Drivers
• Driver Types
• Device Number
• Driver Initialisation
• Module Load/Unload
• Providing Module Parameters
• Open and Release Functions
• Read and Write
• Write
• Reading from Device
• Read Code
• Tasklet and Bottom Half Code
• Interrupt and Tasklet Code

Further Pointers

• Pointers to Pointers
• Using Pointers to Pointers to Structures
• Pointers to Constant Values
• Constant Pointers
• Increment Operators and Pointers
• Pointers to Functions
• Initialising Function Pointer Values
• Calling Functions Through Pointers
• Call-Back Functions
• Arrays of Pointers to Functions
• Function Pointers for State Machines
• State Machine Example: a Toaster

Building Software with Make

• Introduction
• Different Versions of Make
• A Simple Project
• Software Building Concepts
• Targets and Prerequisites in Make
• Building an Object File with Make
• Pattern Rule Variables
• Building an Executable with Make
• Rebuilding When Prerequisites Change
• Default Rules
• Substitution References
• Implicit Rules
• Configuring Implicit Rules
• Adding More Rules
• Advanced Features

Advanced Use of the Preprocessor

• Parametric Macros
• Problems with Macros
• Macros and Scope
• Macros and Precedence
• Testing Assertions
• Stringification
• Assertions with Side Effects
• Token Pasting
• When to Use Parametric Macros

Efficient C Programming

• Basics
• Principal Causes of Inefficiency
• Architecture Issues
• Efficient Algorithms
• Coding Tactics and Compilers
• Difficulties with Code Optimisation
• Common Tricks - Subexpressions
• Using register Variables
• Loop Unrolling
• Space-Time Tradeoffs
• Floating-Point Arithmetic
• Compiler Optimisation
• Avoid Pass-by-Value of Large Objects

MISRA C — Designing Safer C Programs

• In This Module Will Will Cover:
• MISRA C — for Safety-Related Programming
• MISRA C - Rules
• Environment Rules
• Character Sets and Comments
• Identifiers and Types
• Constants
• Declarations and Definitions
• Initialisation
• Operators
• Expressions
• Control Flow
• Functions
• Pre-Processor Directives
• Pointers and Arrays
• Structures and Unions
• Standard Libraries
• MISRA C Tools
• References for MISRA C and Safer C