Caleb Davis & Nathan Smith

Developing firmware is an essential skill that cyber security professionals should be familiar with to gain a deeper understanding of the foundation of most systems that are being relied on. Additionally, a fundamental understanding of firmware development is a valuable asset in the realm of firmware reverse engineering. This hands-on workshop aims to tackle both directions of firmware (development/reversing) to give the audience a better understanding of the intricacies with each process. The firmware development portion of the workshop will walk the audience through a guided activity that performs the basic steps to deploy a firmware application on an embedded microcontroller (STM32). The application will be developed in such a way that it is intended to be reversed. The second half of the workshop deals with the firmware binary and the steps necessary to fully recover the firmware as much as possible. An important note is that these tools and firmware will be open-source and therefore the audience can attempt this work on their own. Takeaways from this talk include an understanding of bare metal development environments, embedded C code, memory mapping and peripherals, as well as an intermediate understanding of Ghidra.