Book Image

The Insider's Guide to Arm Cortex-M Development

By : Zachary Lasiuk, Pareena Verma, Jason Andrews
Book Image

The Insider's Guide to Arm Cortex-M Development

By: Zachary Lasiuk, Pareena Verma, Jason Andrews

Overview of this book

Cortex-M has been around since 2004, so why a new book now? With new microcontrollers based on the Cortex-M55 and Cortex-M85 being introduced this year, Cortex-M continues to expand. New software concepts, such as standardized software reuse, have emerged alongside new topics including security and machine learning. Development methodologies have also significantly advanced, with more embedded development taking place in the cloud and increased levels of automation. Due to these advances, a single engineer can no longer understand an entire project and requires new skills to be successful. This book provides a unique view of how to navigate and apply the latest concepts in microcontroller development. The book is split into two parts. First, you’ll be guided through how to select the ideal set of hardware, software, and tools for your specific project. Next, you’ll explore how to implement essential topics for modern embedded developers. Throughout the book, there are examples for you to learn by working with real Cortex-M devices with all software available on GitHub. You will gain experience with the small Cortex-M0+, the powerful Cortex-M55, and more Cortex-M processors. By the end of this book, you’ll be able to practically apply modern Cortex-M software development concepts.
Table of Contents (15 chapters)
1
Part 1: Get Set Up
5
Part 2: Sharpen Your Skills

Example 1 – Secure versus non-secure hello world

In general, when you start a new project for an Arm Cortex-M device with TrustZone (such as the Cortex-M33 and Cortex-M55), the project will comprise two sub-projects: a secure and non-secure project. Secure and non-secure code have their own boot code and are compiled and linked independently in the sub-projects. Both secure and non-secure code run on the same processor but are loaded in isolated and independent areas of memory. All the code that handles security and configuration, such as boot code, firmware updates, and crypto libraries, is placed in the secure project. The rest of the application code is placed in the non-secure project. The objective is to minimize the amount of code in the secure project and run exhaustive checks on it for security vulnerabilities.

Important note

The implementation of secure software with TrustZone inherently follows the 10 security goals – specifically, Goal 7 of isolating...