Building and Validating FreeRTOS-Based virtual ECUs with Synopsys Silver: A Comprehensive Approach

Virtual ECUs (vECUs) have significantly changed software development and testing within the automotive industry. By simulating the functionality of physical ECUs in a virtual environment, vECUs facilitate quicker software development and validation, and significantly reduce the need for physical hardware. This allows software teams to initiate development and testing even in the beginning when no actual hardware is available. More importantly, enabling Software-Defined Vehicle (SDV) processes, such as Continuous Integration and Continuous Deployment (CI/CD), utilize vECUs throughout the entire software lifecycle, and enable the fastest feedback on code changes and bug-fixes.

Therefore, it is crucial for leading Software-in-the-Loop (SIL) tools like Synopsys Silver™ to address the latest industry requirements by supporting the virtualization of open-source operating systems such as FreeRTOS. This enables customers to use Silver in known comprehensive workflows to build vECUs. It was never simpler to generate FreeRTOS-based vECUs for deterministic and reproducible SIL test execution.

On the other hand, FreeRTOS does not provide an automotive-grade middleware stack and associated tooling out of the box. Essential middleware functions like communication, diagnostic, or system state management are missing and force the OEM developers to find individual solutions. Thus, it is not a surprise that today’s OEMs experiment with hybrid solutions based on FreeRTOS & AUTOSAR Classic modules.

In fact, it comes with its own set of challenges:

While AUTOSAR is still the dominant solution for safety-critical ECUs, with SAFERTOS² we’re seeing a solution also to use FreeRTOS in safety critical systems. Additionally, we’re seeing a clear market transformation for:

• Microservice-based architectures
• Zone controllers
• Software-defined vehicles

These concepts demand modular, scalable software – and for many domains, AUTOSAR Classic is too rigid and resource-heavy. FreeRTOS is filling the gap and is gaining share. 

The listed features by far exceed the capabilities of other RTOS simulators, which clearly lack the requirements of automotive software development and testing teams and their supply chain.

The solution lends itself to shift left not only start of production (SOP) dates, but also technological assessments and decision making as described above. For instance, porting resource intensive AUTOSAR Classic software components to a lightweight RTOS-based stack running on a separate core.

The associated video in this blog showcases how to debug a Silver vECU that runs an Onboard Charging software component on top of FreeRTOS in addition to a MICROSAR-based Battery Management System distributed on two cores.

In summary, the advanced feature set outlined here positions this vECU solution as a transformative tool for automotive software development and validation. Its integration capability, deterministic simulation, multi-core realism, and flexible runtime options empower engineering teams to accelerate production timelines and make informed technological decisions early in the process. By supporting industry standards and offering compatibility across platforms, it surpasses conventional RTOS simulators and stands as an essential asset for modern automotive software projects.