In the modern landscape of embedded software development, efficiency and safety are paramount. As applications become more complex and demands on performance and security increase, developers turn to every tool in their arsenal to meet these challenges. Enter std::uintptr_t, a data type that, while not new, is sadly overlooked in most embedded codebases. This guide aims to introduce std::uintptr_t, showcasing its benefits and demonstrating how to use it effectively in your projects. This arti...| Sticky Bits - Powered by Feabhas
The Challenge of Fixed-Size Integers Before C99 In embedded programming, before adopting the C99 standard (ISO/IEC 9899:1999), a significant challenge was ensuring the consistent sizing of key data objects. This complexity stemmed from the C standard’s (ISO/IEC 9899) non-committal stance on the size of an int. We knew: A short is a minimum of 16-bits. A long is a minimum of 32-bits. An int is somewhere between a short and a long. This flexibility boosted C’s portability, making it a favou...| Sticky Bits - Powered by Feabhas
Introduction When we developed the CMake based toolchain for our training projects we used a shell script to simplify invoking the cmake command line. CMake 3.19 added a presets feature that allows us to define command line parameters in a CMakeSettings.json file which can be used in place of using multiple command parameters. In previous articles about CMake we have shown how we need to specify command line parameters to use CMake with an embedded target toolchain (see CMake Part 3). T...| Sticky Bits - Powered by Feabhas
BlackHat Europe 2022 During the first week of December, I had the pleasure of attending a training course at BlackHat Europe 2022 titled Assessing and Exploiting Control Systems and IIoT run by Justin Searle. Part of the course involved Assessing and Exploiting Embedded Firmware by reading on-chip Flash using OpenOCD. Unfortunately, we ran out of time to finish the last labs during the training (we ran 9 am-6 pm each day). So I decided to follow along with the very comprehensive notes [...]| Sticky Bits - Powered by Feabhas
Dynamic polymorphism (virtual functions) is central to Object-Oriented Programming (OOP). Used well, it provides hooks into an existing codebase where new functionality and behaviour can (relatively) easily be integrated into a proven, tested codebase. Subtype inheritance can bring significant benefits, including easier integration, reduced regression test time and improved maintenance. However, using virtual functions in C++ brings a runtime performance overhead. This overhead may appear inc...| Sticky Bits - Powered by Feabhas
Creating a flash image The primary purpose of the ihex file in the embedded space is to create a file that is used to program/reprogram a target system. There are various file formats around, with the Intel Hex (ihex) format being among the most widely used. The output of the linker stage of a build process is typically to generate a .elf file (Executable and Linkable Format). Many debuggers and programmers can work directly with the ELF file format. However, in many [...]| Sticky Bits - Powered by Feabhas
In my first blog post about C++20 Coroutines I introduced the concepts behind a synchronous or generator style coroutine and developed a template class to support coroutines for any data type. In this post I’ll add an iterator to the template to support the range-for loop and iterative algorithms. You may want to review that post before reading this one but the following code should act as a reminder about how to write and use a coroutine to read two floating [...]| Sticky Bits - Powered by Feabhas
Introduction In previous blog posts in this series (Part 1, Part 2 and Part 3), I looked at using CMake on a Linux host to configure a build to cross compile to target hardware such as the STM32F4 Series. In this post, we’ll work with the GNU Arm Embedded Toolchain on a Windows 10 Host. The first part of this blog discusses running the Windows hosted versions of CMake, GNU Arm Embedded Toolchain and GNU Make. An alternative approach, briefly discussed at the [...]| Sticky Bits - Powered by Feabhas
C++20 Coroutines There seems to be a lot of confusion around the implementation of C++20 coroutines, which I think is due to the draft technical specification for C++20 stating that coroutines are a work in progress so we can’t expect full compiler and library support at this point in time. A lot of the problems probably arise from the lack of official documentation about working with coroutines. We have been given C++ syntax support for coroutines (the co_yield and co_return) but without [...| Sticky Bits - Powered by Feabhas
Ceedling is still probably the best Test-Driven Development (TDD) environment for C programmers out there. But, as with many Free Open-Source Software ( FOSS ), tools getting it to work natively on a Windows environment involves the odd hoop-jumping exercise; either involving messing around with the likes of Cygwin or Mingw; or using a full Virtual Machine (VM) environment such as VirtualBox or VMware. However, with the introduction of Windows-Subsystem-for-Linux (WSL) and the much-improved u...| Sticky Bits - Powered by Feabhas
In this post, by Embedded I’m generally referring to deeply embedded/bare-metal systems as opposed to Linux-based embedded systems. Embedded systems and strings Historically, the need for and thus the use of strings in embedded systems was fairly limited. However, this has changed with the advent of cheaper, full graphic displays and the growth of the ‘Internet of Things’ (IoT). Many embedded systems sport full-colour graphics displays, supported by embedded-specific graphics libraries,...| Sticky Bits - Powered by Feabhas
