AUTOSAR Classic
The established standard software architecture for deeply embedded, real-time automotive ECUs — statically configured and safety-oriented.
AUTOSAR Classic is the standardized software architecture for deeply embedded automotive ECUs, maintained by the AUTOSAR development partnership since 2003. It targets controllers with hard real-time requirements and limited resources — engine control, braking, body functions — running on microcontrollers rather than application processors.
The Classic platform defines a layered stack: a real-time operating system based on OSEK, standardized basic software modules (communication, memory, diagnostics), and a runtime environment (RTE) that connects application software components through formally described interfaces. Everything is statically configured at build time, which supports determinism and safety certification up to the highest ASIL levels, but rules out installing new software after deployment.
That static nature is why Classic coexists with, rather than being replaced by, AUTOSAR Adaptive in modern architectures: zone controllers and safety-critical ECUs stay on Classic, while dynamic, updatable applications run on Adaptive or other POSIX-based platforms.
Related: AUTOSAR Adaptive · E/E architecture · Middleware (automotive)