Linux Embedded System C++ Programming

Duration: 5 Days

Course Background

This course is designed for experienced C programmers with some experience of either embedded system or Win32 API or POSIX API programming, but who have little experience of either C++ programming, or object oriented programming or both. As well as providing a fast paced introduction to the C++ programming language the course also explores topics that are paraticularly relevant to embedded systems developers such as C++11 multi-threading, C++ Stream Libraries and C++ Network and Asynchronous IO programming. The course will also overview C++ approaches to user space GPIO, RS232 serial and I2C/SPI serial C++ programming.

Course Overview

This intensive, fast paced course enables experienced C programmers to begin writing embedded C++ software. It covers all the commonly used features of the C++ language and provides insights into the strengths and limitations of these features in the context of implementing embedded applications. Additionally, the course discusses the implemention of C++ class wrappers around C-based operating system APIs and TCP/IP socket APIs and explores C++ techniques for working with GPIO and with serial protocols such as RS232, SPI and I2C.

Practical work uses the GNU C++ compiler running on a Linux workstation, as well as cross-compiling projects to run on embedded Linux platforms. The platforms used on the course will be the RaspberryPi and the BeagleBone Black. Projects are built using both the traditional command-line-and-Makefile approach, and also using an Eclipse based C++ Integrated Development Environment. Applications are run on a PC running one of the standard Linux distributions, and also on an ARM board running embedded Linux.

Course Benefits

Migrating from C to C++ is challenging task if the true benefits of using C++ are to be realised. Unless careful thought is given to Analysis and Design, the resulting code may be little more than C code with C++ wrappers, with little or no gain in productivity through using an object-oriented language.

The real benefits of C++ come from:

Expertise in object oriented analysis and design
An understanding of object oriented programming patterns and idioms
The ability to identify and use existing C++ frameworks, or to design and implement new frameworks from scratch
Experience with the C++ STL (Standard Template Library) and the Boost C++ libraries

On completing this course you will

Have a sound understanding of UML Notation to specify C++ applications and an ability to think and work with objects as the underlying abstraction
Understand polymorphism and be able to identify situations where the use of polymorphism in an embedded system environment is appropriate
Be able to make the best use of constructors and destructors, delete and new operators and understand key idioms and patterns such as reference counting, copy on modify, and the Singleton.
Be able to write C++ code that can access embedded system hardware
Understand the advantages and disadvantages of wrapping C operating system API calls in C++ classes
Understand C++ exception handling and the C++ RTTI (Run Time Type Identification) mechanism, and identify situations where their use is appropriate (or not)
Be aware of object oriented patterns and their uses
Be aware of framework oriented approaches and their uses
Appreciate how to realise dynamic data structures and their associated algorithms in C++
Understand the principles underlying templates and the STL, and decide where the use of templates and the STL is appropriate
Be aware of C++ techniques for implementing small memory systems
Be able to build applications that combine C++, C and assembler and that reuse existing C code and libraries
Understand basic principles and strategies for wrapping operating system API functions in C++ clases - e.g. for multi-threading and inter-process communication
Understand the design underlying the C++ IOSTREAM classes, where to use them in embedded applications, and where to use low level I/O in the C standard library instead.

Course Contents

Brief History of C++

C++ as an extension of C
C++ as an evolving language and the development of the ANSI C++ standard
Possible memory and performance costs of using C++ in embedded applications
Overview of new features in C++ 11

Review of the C in C++

Base data types (numeric char, integer and floating point types)
Pointers and arrays
Function prototypes and function pointers
structs , pointers to structs and dynamic data structures
typedefs, enums and macros
I/O in C
Replacing C based I/O (printf, scanf etc) with C++ based I/O

Functions in C++

Function overloading
Name mangling / decorating
Mixing C and C++ code modules (use of extern C)
Operators and operator overloading in C++

Key Object Orientated Concept - Classes and Instances

Member variables and member functions (private, public, protected)
Constructors and destructors
Default constructors and default destructors
Initialiser lists
Derived classes
Arrays of classes
UML class diagram notation

More advanced aspects of working with classes and instances

Copy constructors
Deep vs. shallow copying
Virtual functions and virtual classes (compile time vs. run time binding)
Implementing dynamic data structures using classes (linked lists, binary trees, etc)
Friend classes and friend functions
Static member variables and static member functions
Templates and the Standard Template Library

A more detailed look at input and output in C++

The C++ iostream classes
Overloading the insertion and extraction operators for use with user defined classes
Reading and writing files
Basics of object and data persistence

Dynamic memory management

The new and delete operators
Overloading the new and delete operators
Application specific memory management

Exception Handling

The concept and structure of exceptions and exception handling
Throwing an exception
The try block
Catching an exception
Re-throwing exceptions
Catch-all handlers
Exception specifications
Exception handling implemention mechanisms
Appropriateness of exception handling in embedded applications
Alternatives to the C++ exception handling mechanism

Templates and their uses

Data parameterised collections of classes and functions
How C++ compilers handle templates
The C++ Standard Template Library - a brief overview
The Boost C++ libraries - a brief overview

Namespaces - an extra level of scoping

usefulness of namespaces in large projects and when re-using code

Mixed C and C++ applications and extern C
Mixed C++, C and assembler applications

Calling assembler from C
Calling assembler from C++

Structured use of the Posix API in C++

Task and thread creation and management
Semaphores, mutexes and conditional variables
Memory mapping and inter-process communication
Sockets API in C++ - TCP/IP Sockets libraries
File IO

Accessing peripherals and devices from user space

Patterns and idioms for accessing hardware from C++ in User Space Linux applications
Patterns and idioms for bit manipulation in C++
Memory mapping and access to memory mapped device registers from user space
Polling techniques for synchronous I/O
Working with I2C and SPI devices
Working with RS232 and RS485

GCC Compiler Specific Extensions to C++