Ensuring High-Quality Code for Embedded Systems: Best Practices and Tools

Despite remarkable advancements in technology, remotely updating embedded systems remains a complex challenge. For embedded software engineers, ensuring robust code quality is paramount, even more so than in other areas of software development. Given the unique nature of embedded systems, careful attention to code quality, scalability, and the ability to handle dynamic product goals and market forces is essential. Here’s an exploration of the tools, strategies, and best practices embedded specialists are using to develop and maintain high-quality code that meets evolving requirements.

Key Tools for Maintaining Code Quality in Embedded Systems

One of the key challenges in embedded systems development is ensuring that updates are seamlessly deployed across devices. Automating the build, test, and deployment processes is essential, and tools that facilitate continuous delivery (CD) and integration (CI) have proven highly effective.

Continuous Delivery (CD) Tools

To ensure a smooth and automated deployment process, using industry-standard CD tools is crucial. Popular platforms like GitHub, GitLab, Jenkins, and Azure DevOps help automate the creation of executables (binaries) that are ready to be flashed onto devices. These platforms enable efficient workflows for building, testing, and packaging embedded applications, ensuring code is consistently deployed to different environments.

These tools support a robust setup that allows every code change to trigger automated tests, preventing any new code from being merged into the main production code without passing necessary verification gates. This includes static code analysis to catch potential errors or bugs before they can affect the system.

Static Analysis and Code Quality

Static analysis is an indispensable part of the code quality assurance process. Tools for static code analysis check for errors, potential vulnerabilities, and performance bottlenecks that may not be immediately visible during development. By integrating static analysis into the development pipeline, teams can identify issues early, improving the overall robustness of the system. Tools like Clang Static Analyzer, SonarQube, and Coverity are frequently used in embedded environments to enforce these standards.

Containerized Development Environments

Consistency in development environments is a major challenge in embedded systems development, especially when multiple developers and teams are involved. Containerized environments have become an effective solution to this problem. Containers ensure that everyone works in the same environment, eliminating issues like “it works on my machine.”

A container for embedded systems development typically includes:

• Compilation Toolchain: Necessary tools to compile code for embedded targets.
• Static Analysis Tools: To continuously monitor and improve code quality.
• Debugging Tools: To diagnose and fix issues effectively.
• Libraries and Dependencies: Pre-installed libraries to support application development.

The advantage of containers is clear: new team members can get up and running quickly, and updates to the development environment are instantly propagated to all team members. However, licensing challenges can arise, especially if the project relies on proprietary tools. In such cases, leveraging open-source alternatives can reduce costs and simplify development.

Virtual Machines as an Alternative

Another approach is using virtual machines (VMs), which offer similar benefits to containers but with some trade-offs. VMs provide isolated environments, ensuring that the development setup is identical across all team members. However, they are more resource-intensive compared to containers, requiring significant computing power to run effectively.

Automated Testing in Embedded Systems Development

Automated testing is a fundamental part of ensuring code quality and functionality in embedded systems. By running automated tests after every code change, teams can ensure that new changes do not introduce regressions or break existing functionality. The main types of automated tests for embedded systems are:

1. Smoke Testing

Smoke tests are the first line of defense in ensuring that a device’s most critical features function as expected. These tests verify basic functionality—such as turning the device on and ensuring it doesn’t catch fire! Smoke tests help confirm that the embedded system is “alive” and can perform its essential tasks before more extensive testing is carried out.

2. Integration Testing

Integration tests validate that all components of the codebase work together after changes are implemented. These tests ensure that different modules of the system can interact as expected, providing confidence that the overall system functions properly in a real-world scenario. Integration tests typically run in the same environment as smoke tests, but with a more thorough examination of system interactions.

3. Unit Testing

Unit testing breaks down the code into its smallest components, testing each one individually. This is especially useful in Test Driven Development (TDD), where tests are written before the code. Popular frameworks for unit testing in embedded systems include Gtest, Catch2, and Unity (for C projects). Given the hardware-centric nature of embedded development, mocking frameworks like Gmock, FakeIT, and Cmock (for Unity) are essential to simulate hardware interactions and isolate software components during testing.

Additional testing techniques, such as fuzz testing and hardware verification tools, may be employed depending on the product’s requirements.

Code Reusability and Modular Design

One of the best practices for embedded software development is creating code that is reusable and modular. Reusability ensures that the same code can be deployed across different products, saving time and reducing duplication. This is particularly valuable for embedded engineers who design firmware that will be used across multiple devices or platforms.

To facilitate this, embedded engineers should think of firmware as a set of logical modules. Each module should be designed to be reusable in different contexts, and any updates or bug fixes to a module should propagate across all products that use it. Tools like CMake, Meson, and Bazel are essential for managing complex build systems and organizing the firmware compilation process, especially when targeting different hardware architectures.

Unit testing individual modules is also key to ensuring that these modules can be easily adapted for use in different contexts. By maintaining clean, modular code, teams can speed up development and reduce the risk of introducing bugs when repurposing code for new products.

Accelerating Development with External Expertise

While implementing these best practices and tools is critical for ensuring high-quality code in embedded systems, many companies find it beneficial to partner with external embedded engineering teams to speed up development and reduce time to market. Expert teams can help manage development, minimize delays, and ensure the product meets the required specifications.

With years of experience supporting embedded systems projects, Software Mind provides a reliable solution for businesses looking to scale their embedded systems capabilities. Whether it’s building custom firmware for a new device, maintaining legacy systems, or accelerating time to market, Software Mind’s cross-functional, agile teams offer tailored support to meet the specific needs of each client.

Conclusion

The embedded systems development landscape is continually evolving, and maintaining code quality and robustness remains a central challenge. By leveraging modern development tools like continuous integration and delivery systems, adopting containerized or virtualized environments, and implementing comprehensive automated testing, embedded engineering teams can ensure that their code remains reliable, scalable, and adaptable to ever-changing requirements.

At Software Mind, our team of embedded systems specialists can help you implement these best practices and more, ensuring your products meet the highest standards while reducing development costs and time to market. If you’re looking to enhance your embedded systems development processes, get in touch with us today to learn more about our services and how we can support your next project.