C and C++ Programming for embedded systems

Deeper description

You might be a pretty good programmer but have no experience in C or C++.  You might even know some C or C++ but have only ever used these skills on traditional IT settings.  This course will teach you about how programming for embedded systems is different.  We look at low-level concepts such as cross compilation, memory issues and address-based peripheral access, as well as some of the higher level challenges such as the implications of resource constrained devices and the use of ASLR.

There is a certain amount of theory to cover in this module.  Yes we will do things like for loops and variable types, but that is because these concepts and the knowledge to apply them are all needed later in the module.  The emphasis throughout this module though is for it to be practical with theoretical support.

Strictly speaking this module isn’t about hacking badly written embedded applications.  Instead its about writing them.  Yes, you read that correctly, the code you produce is likely to be insecure.  This is to enable the module to work through some of the cyber security implications of the code that is in front of you as well as enabling you to see different ways of achieving the same results.  That last part is actually really important, in other modules we look at code that has been decompiled and in order to be able to recognise what those assembly functions are up to, you need to know what the possibilities are.

Without wanting to ruin the surprise we can also reveal that we have devised a cunning plan.  Our plan is a way of getting you all to develop your embedded C and C++ programming knowledge and skills, but with a cyber security emphasis.  This module will give you all of that whilst also simultaneously preparing you for your new career as a cyber criminal mastermind and all things evil for embedded systems.  *Maniacal laugh not included.

Module contents

This list shows the various main topics we cover during the module:

• Working with different versions of C
• Development environments
• Compiling and cross compilation
• Data types
• Pointers, values, references and dereferencing
• Core concepts such as loops, functions, general logic operations and so on
• Class structure and Object Oriented Programming (OOP)
• Libraries and modules and static compilation
• Memory concepts such as memory maps, access types of memory, management and garbage collection, and safety issues
• Common mistakes both security and non-security related
• Unsafe functions and why they are fun bad
• Efficient code for embedded systems and their trade-offs
• Code obfuscation techniques
• Interacting with peripherals, for example and GPIO
• C / C++ vs Embedded C / C++
• Execution entry points
• Bare-metal programming
• More advanced embedded system programming techniques such as networking and routing, message queueing, event driven code and threading

Why this is good for you

Fundamentally this module will enable you to produce working code on embedded systems. It covers a lot of the common ground that would be found in traditional C and C++ programming courses, but it extends this by looking at the unique approaches and challenges that are present with embedded system programming.  As you leave this course you will have produced working code, you will have interacted with hardware at a very low level, and you will have completed this on an embedded device.  This module isn’t just about having nerdy fun its about bringing a whole new dimension to you, either professionally in the work that you do, or personally by enabling you to build digital systems that achieve things in the physical world.

As this is a cyber security course, this module might seem a little misplaced.  We see why that might be the case.  From our experience, the best hackers and penetration testers out are those who have used, built, maintained and developed the type of systems they are now trying to attack.  The objective of this course is to produce individuals that are well prepared, highly skilled and capable of taking on the cyber security concerns of the age of embedded systems.  Don’t worry though, we maintain a cyber-security focus throughout the module and the practical elements of this module will really bring that home.

With this experience and information you will be able to look at embedded code written in C and C++ and be able to understand what it is doing as well as be able to contribute to its extension.  You can take this new knowledge and confidence and use it to take your career into the hardware hacking scene, expand the types of penetration test you take on, or just show off to your mates.

Prerequisites

There are no formal prerequisites, but the C programming for Embedded Systems module is highly technical.  Experience of programming concepts is needed but you don’t have to have prior experience of C or C++.  The module is designed to build good foundational knowledge first and then dig into increasingly interesting stuff as the days progress.  It also works as a brilliant primer for two of our other modules: Software Reverse Engineering (SRE) and Firmware Reverse Engineering (FRE).