Scaling Firmware Development is Surprisingly Easy

Introduction

As embedded systems become more complex, project scalability becomes a major concern. The diversity of platforms, tools, and hardware configurations often hinders growth, making it challenging to develop firmware that can easily adapt as requirements change. This article will explore how the inherent complexity in embedded systems can obstruct scalability and offer practical strategies to overcome these hurdles.

Modern embedded projects tend to face growing complexity due to factors such as custom hardware, real-time requirements, and resource constraints. These factors slow down development cycles and make scaling difficult, but with the right strategies, teams can scale their firmware development process smoothly.

Challenges in Embedded Firmware Development

Scaling embedded firmware projects comes with several unique challenges, such as:

Hardware Dependency

Firmware often ties directly to specific hardware, meaning that significant changes must occur when switching platforms. This tight coupling can make it nearly impossible to reuse code across different hardware ecosystems without reworking significant portions.

Resource Constraints

Embedded systems operate within strict memory, processing power, and energy consumption limits. Adding more features or expanding a firmware project often requires balancing resource consumption without compromising performance or functionality. Scaling under these conditions demands careful planning.

Monolithic Codebases

Many firmware projects start as tightly integrated, monolithic codebases, making it difficult to reuse or adapt the code to other projects or systems. This lack of modularity not only inhibits scaling but also creates maintenance challenges as the project evolves.

Manual Deployment and Testing

Embedded systems often rely heavily on manual testing and deployment, which becomes unmanageable as projects scale. Without automation, the time required to test new features or validate bug fixes can grow exponentially, leading to bottlenecks. Automation also provides repeatability, for example in cases where a precise value or measurement must be achieved. In this way it also helps ensure complete test coverage.

Vendor-Specific Ecosystems

Relying on proprietary development toolchains and libraries locks firmware into a specific vendor’s ecosystem. This reliance can create challenges when migrating between hardware platforms, as it increases the difficulty of code portability.

Real-Time Requirements

Many embedded systems have strict real-time requirements that necessitate precise timing and performance constraints. It is also important to track these changes over time, for example in super loop-based applications where a change will affect other parts of the system. As systems scale, maintaining these real-time capabilities without degrading performance adds another layer of complexity.

Key Strategies for Making Firmware Scalable

Scaling firmware requires deliberate strategies to improve flexibility, modularity, and automation. Here are some proven approaches:

1. Modular Code Architecture

Breaking down firmware into independent, reusable modules is crucial for achieving scalability. By using a modular code architecture, teams can swap components, add features, or switch hardware with minimal rework. A prime example of this is the use of Hardware Abstraction Layers (HALs), which decouple hardware-specific code from application logic. This enables developers to reuse core logic across multiple platforms, only needing to adapt the HAL for new hardware.

2. Automated Testing

Automated testing allows teams to catch bugs earlier, reducing manual effort and ensuring new features don’t disrupt the system. In embedded systems, a combination of blackbox, greybox, and whitebox testing is often used alongside unit, integration, and Hardware-in-the-Loop (HIL) testing. Frameworks like Ceedling (with Unity and CMock) are effective for whitebox and unit testing, while Tessy automates blackbox testing for embedded software. Greybox testing can be supported by custom scripts or hardware simulations. These approaches help create a scalable, robust framework that adapts as the project evolves.

3. Containerized Development Environments

Using containerized environments, such as Docker, helps maintain consistency across development setups by packaging the entire toolchain and dependencies in a controlled environment. This approach facilitates repeatable builds, ensuring that the same code produces the same results, regardless of where it’s run.

While this reduces configuration mismatches, it doesn’t guarantee repeatable builds in all cases, as minor differences in host systems or container versions can sometimes introduce variation. One caveat with Docker is its limitations in cross-platform compatibility, particularly with newer Apple Silicon Macs.

While Docker images typically work well across Linux, Windows, and older macOS systems, they may require specific configurations or the use of alternative container solutions like Lima or Colima to ensure compatibility with Apple Silicon. Another option is to have your team install and use a specific version of a specific compiler.

4. Automation through CI/CD Pipelines

Continuous Integration (CI) refers to the process of automatically integrating code changes into a shared repository, followed by an automated build and testing process. Continuous Deployment (CD), on the other hand, takes this a step further by automatically deploying the tested code to production or a target environment.

In the context of embedded development, where hardware-specific builds and extensive testing are critical, CI/CD pipelines help streamline development. Automation is key here: after code is pushed to the repository, the CI process builds the firmware, runs tests (such as unit, integration, or hardware-in-the-loop tests), and reports results. CD pipelines then deploy the firmware to the hardware or test environments, all without manual intervention. This accelerates iteration cycles, enhances collaboration between teams, and reduces human error.

A Note on Cross-Platform Code and Tool Flexibility

When building firmware, it’s essential to prioritize tools and frameworks that allow code portability across different platforms. By choosing cross-platform solutions, developers minimize the rework needed when switching between hardware ecosystems. Tools such as Zephyr OS or FreeRTOS offer portability and prevent lock-in to specific vendor ecosystems. This enables the reuse of core features without redeveloping them for each new hardware platform.

Making the Implementation of These Strategies Easier

While Scaling firmware development can seem daunting, the following tips can ease the transition:

1. Collaborate Across Teams with Version Control

Using robust version control systems like Git allows multiple teams to work on the same project simultaneously. This prevents conflicts and ensures smooth collaboration as the project scales.

2. Build and Design with Scalability in Mind

Architecting scalable systems from the outset is a proactive way to ensure your firmware can grow without issues. By thinking ahead and designing for modularity, abstraction, and robustness, teams can future-proof their projects for increased complexity.

3. Adopt Best Practices for Code Modularity

Designing for scalability starts with modular code. Applying best practices like HALs or other abstraction layers ensures that application logic remains separate from hardware concerns, making it easier to scale the project to different platforms or add new features incrementally.

4. Utilize Pre-Built Testing Frameworks

Rather than building a testing framework from scratch, developers can use existing solutions like Unity or Google Test for unit testing, or CMock for mocking hardware behavior. These tools automate quality checks, significantly reducing the burden of manual testing.

5. Leverage Automation Tools

Modern DevOps tools make setting up CI/CD pipelines easier than ever. Tools like GitLab CI, Jenkins, or even simpler automation scripts can help create automatic build, test, and deployment flows without needing to invest excessive manual effort.

6. Implement Containerized Environments

By using container platforms such as Docker, teams can create standardized development environments that work across different hardware setups. This ensures consistent builds, helps eliminate configuration mismatches, and reduces the friction of onboarding new team members.

7. Invest in Development Process Optimization

Regularly reviewing and improving development processes is crucial for staying ahead as projects grow. Incorporating DevOps practices and streamlining workflows enhances collaboration, speeds up deployment, and improves overall productivity.

Conclusion

As embedded systems become more sophisticated, scaling firmware development is more important than ever. However, by adopting the strategies outlined above— modular code architectures, automation, cross-platform tools, and best practices—teams can overcome the traditional barriers to scalability. Speak to us at Dojo Five for help with implementing these practices to future-proof firmware projects, allowing teams to meet evolving requirements, improve efficiency, and maintain flexibility as system complexity grows.