AUTOSAR - Software Architecture

Software Architecture

To make a component based design possible, the AUTOSAR-project uses a layered architecture that ensures the decoupling of the functionality from the supporting hardware and software services.

• Basic Software Layer: the Basic Software is standardized software that does not have any functionality but offers hardware-dependent and hardware-independent services to the layer above (the Run Time Environment). This is realized through the use of Application Programming Interfaces. This layer itself is not entirely hardware independent but makes the upper layers hardware independent.

• Runtime environment: handles the information exchange between the application software components and connects the application software components to the right hardware. This layer decouples the application software components from the hardware as well as the application software components from themselves.

• Application Layer: the application layer is the only layer that is not composed of standardized software, it is also the layer where the actual functionality is situated. The layer is composed of application software components that interact with the run time environment.

The Basic Software and Runtime Environment are the technical realization of the virtual function bus in the design model.

The layered architecture is used on every ECU and makes it possible to design a vehicle system without thinking in terms of ECUs. The designers select a number of software components that do not know on which ECU certain software components are installed or hardware is connected. The Runtime Environment makes sure that the software components can communicate with one another or with the hardware, without concern if both components are on different ECUs or not.