Automotive trends like autonomous driving, v2x connectivity, OTA updates, predictive maintenance, and many other innovative features are based on in-vehicle software functions. For all these functions to work seamlessly and to cater to real-time in-vehicle functionalities, each ECU (electronic control unit) must work efficiently. Modern-day high-end vehicles have up to 100 ECUs, which communicate with each other via CAN bus, CAN FD, or Ethernet network to support complex vehicular functions. 

Earlier, ECU (electronic control unit) software used by OEMs were on different platforms. There was no standard software architecture that was being used by tier 1 suppliers and their vendors to design the ECU software for OEMs. So, whenever any OEM wishes to switch to a new tier 1 supplier or vice-versa, the transition was very difficult. The new supplier used to face enormous challenges in understanding the existing software architecture, hardware platforms, and standards used in ECU software development. Thus, it was impossible for a new supplier to drive an on-going project from the midst of its production life cycle. 

To streamline the coordination between OEMs and tier 1 suppliers, to improve ECU software quality and reduce development time and costs, tier 1 automotive suppliers, semiconductor manufacturers, software suppliers, tool suppliers, and others came forward in 2003 and created a consortium called AUTomotive Open System ARchitecture (AUTOSAR). Core partners and autosar partners, including premium partners, played a key role in establishing the AUTOSAR framework and guiding its organizational structure and strategy. 

Since its creation, autosar development has become the industry standard for creating automotive embedded software. The use of standardized architecture, tools, and processes in autosar development has enabled more efficient, reliable, and scalable software solutions for electronic control units across the automotive industry. 

Introduction to Automotive Open System Architecture 

The Automotive Open System Architecture (AUTOSAR) is a global development partnership dedicated to creating a standardized software architecture for automotive electronic control units (ECUs). Established in 2003, AUTOSAR unites automotive manufacturers, suppliers, and leading companies from the electronics, semiconductor, and software industries to collaborate on a common software platform. This initiative has transformed the way automotive software is developed, enabling the creation of scalable, portable, and hardware-independent ECU software that meets the increasing complexity of modern vehicles. By providing a unified software architecture, AUTOSAR streamlines the development of software components, communication services, and runtime environments, making it easier for different manufacturers and suppliers to work together. This standardization not only enhances the efficiency and reliability of automotive software but also supports the rapid evolution of automotive electronic control units and the broader automotive software industry.

What is AUTOSAR?

Automotive Open System Architecture (AUTOSAR) is an open and standardized automotive software architecture, which supports standardization in interfaces between application software and basic vehicular functions, and it helps in establishing common ECU software architecture for all the AUTOSAR members. These standards and interfaces are defined by detailed technical specifications, which ensure interoperability and compliance across different implementations. 

AUTOSAR is intended to provide inherent benefits to the members to manage increasingly complex E/E in-vehicle environments like easy integration and exchange of functions in complex ECU networks and control over the entire product lifecycle. AUTOSAR encompasses multiple autosar platforms, including both the Classic and Adaptive platforms, each designed to address specific requirements in automotive applications. 

The layered structure of AUTOSAR, including Application Software, Runtime Environment, and Basic Software, is known as the autosar classic platform architecture, which is particularly suitable for embedded systems with real-time and safety requirements. 

AUTOSAR Standard

The AUTOSAR standard serves as a comprehensive framework that defines the software architecture for automotive ECUs, supporting both current and future vehicle technologies. It is built around two main platforms: the AUTOSAR Classic Platform and the AUTOSAR Adaptive Platform. The Classic Platform is tailored for traditional automotive domains such as powertrain, chassis, and body electronics, where real-time performance and safety are critical. In contrast, the AUTOSAR Adaptive Platform is designed for high-performance computing applications, including autonomous driving and Car-to-X communication, where flexibility and scalability are essential. The AUTOSAR standard introduces a layered architecture, consisting of the application software layer, runtime environment, and basic software layer. This structure enables hardware-independent development, allowing software components to be reused across different ECUs and hardware platforms. By adhering to the AUTOSAR standard, automotive manufacturers and suppliers can achieve greater interoperability, scalability, and reliability in their software development processes, ensuring that complex automotive systems function seamlessly together.

AUTOSAR Architecture

AUTOSAR is an open system architecture for automotive software development and provides standards for developing common automotive software applications. It is a growing and evolving standard that defines a layered architecture for the software. The AUTOSAR architecture consists of three major layers, also referred to as three software layers or major layers. The classic AUTOSAR platform runs on a microcontroller and is divided into 3 main layers; let us discuss them in detail:

• Basic Software Architecture- It is common to any AUTOSAR ECU.
• AUTOSAR Runtime Environment
• Application Layer

AUTOSAR defines two platforms: the Classic Platform and the Adaptive Platform, each with distinct roles to support different types of vehicle electronic control units (ECUs) and applications.

One essential concept in AUTOSAR architecture is the virtual functional bus (VFB), also known as the virtual bus. The VFB enables abstraction and decoupling of application software from the underlying hardware infrastructure. The VFB handles communication between software components, both within and across ECUs, without requiring detailed knowledge of lower-level technologies. This allows developers to focus on higher-level functionality without needing an in-depth understanding of hardware or communication protocols, supporting hardware-independent development.

Basic Software Architecture (BSW)

AUTOSAR Basic Software Architecture consists of hundreds of software modules structured in different layers and is common to any AUTOSAR ECU. This means the supplier who has designed BSW can share it with other suppliers that are working on ECUs of engine, gearbox, etc.

The basic software is organized into functional groups representing different infrastructural elements such as system, memory, and communication services. These functional groups help define infrastructure and service interfaces, supporting modularity and scalability within the BSW.

Basic software architecture in AUTOSAR consists of three layers:

• Microcontroller Abstraction Layer (MCAL): MCAL is also known as a hardware abstraction layer and implements interface for the specific microcontroller. MCAL has layers of software, which are integrated with the microcontroller through registers, and offers drivers like system drivers, diagnostics drivers, memory drivers, communication drivers (CAN, LIN, Ethernet, etc.), I/O drivers and more. Complex drivers are included in this layer to handle sophisticated hardware interactions and ensure hardware independence within the ECU software stack.
• ECU Abstraction Layer: The prime task of the ECU abstraction layer is to deliver higher software layers for ECU specific services. This layer and its drivers are independent of the microcontroller and dependent on the ECU hardware and provide access to all the peripherals and devices of ECU, which supports functionalities like communication, memory, I/O, etc. Complex drivers are also present here to manage intricate hardware operations and system functions.
• Service Layer: The service layer is the topmost layer of AUTOSAR Basic Software Architecture. The service layer constitutes an operating system, which runs from the application layer to the microcontroller at the bottom. The OS has an interface between the microcontroller and the application layer and can schedule application tasks. The service layer in BSW is responsible for services like network services, memory services, diagnostics services, communication services, ECU state management, and more.

The robustness and reliability of the AUTOSAR Basic Software Architecture make it suitable for deeply embedded systems requiring high reliability and safety.

AUTOSAR Runtime Environment (RTE Layer)

AUTOSAR Run-time Environment is a middleware layer of the AUTOSAR software architecture between the BSW and the application layer and provides communication services for the application software. The RTE provides the full interface for application software to interact with other layers and the underlying hardware, acting as an abstract, hardware-independent communication layer. It manages the communication interfaces between software components and the underlying infrastructure, enabling seamless mapping and decoupling applications from hardware. Additionally, the RTE supports various communication protocols to ensure reliable and secure data exchange across in-vehicle systems and external networks.

Application Layer

The application layer is the first layer of the AUTOSAR software architecture and supports custom functionalities implementation. This layer consists of the specific software components and many applications which perform specific tasks as per instructions. From the application point, developers do not need detailed knowledge of lower-level technologies, as the architecture abstracts these details.

The AUTOSAR application layer consists of three components: application software components, ports of software components, and port interfaces.

AUTOSAR ensures standardized functional interfaces for software components in the application layer, and application software components help in generating simple applications to support the vehicle’s functions. These functional interfaces are standardized to ensure compatibility and integration across the architecture.

The communication between software components is enabled via specific dedicated ports using a virtual Function Bus. Dedicated ports are used to map application communication interfaces to the virtual bus, facilitating hardware independence and seamless communication. The virtual functional bus enables communication both within an individual ECU and across multiple ECUs. These ports also facilitate communication between software components and AUTOSAR Basic Software (BSW).

The above-explained architecture of AUTOSAR is its classic platform, which supports real-time requirements and safety constraints. Based on the microcontroller, the classic platform is capable of supporting applications in the field of networking and security by allowing ECUs to access vehicle sensors and actuators.

Application Interfaces

Application interfaces are a fundamental aspect of the AUTOSAR architecture, enabling seamless communication between software components and the runtime environment. At the heart of this approach is the Virtual Functional Bus (VFB), an essential concept that provides a standardized interface for application software components to interact with basic software modules and other ECUs. The VFB manages data exchange both within a specific ECU and across multiple ECUs, ensuring that software components can communicate efficiently regardless of the underlying hardware. By defining clear and consistent application interfaces, AUTOSAR makes it possible to develop portable and reusable software modules, simplifying the integration of new features and reducing the complexity of software development. This approach not only accelerates the development process but also enhances the reliability and maintainability of automotive software systems.

High-Performance Computing

The AUTOSAR Adaptive Platform is specifically engineered to meet the demands of high-performance computing in modern vehicles, supporting advanced applications such as autonomous driving and sophisticated driver-assistance systems (ADAS). This adaptive platform introduces a service-oriented architecture (SOA), which enables the development of complex software components and robust communication services. By supporting Linux-based operating systems and POSIX-compliant interfaces, the Adaptive Platform offers greater flexibility and scalability for software development teams. These capabilities allow automotive manufacturers to implement intelligent, data-driven systems that enhance vehicle safety, efficiency, and comfort. As vehicles become more connected and autonomous, the high-performance computing power provided by the AUTOSAR Adaptive Platform is essential for processing large volumes of data and supporting real-time decision-making.

Why Adaptive AUTOSAR?

From 2003 to 2015, Classic AUTOSAR became an established platform and was doing perfectly well to run 60-80 ECUs in a vehicle. With the evolution of IoT based automotive trends like V2X connectivity and automated driving, electrification skyrocketed, and as a result, a huge demand for supporting functions and devices was created in the market. It was discovered that the existing classic AUTOSAR platform was not suitable to support these mega-trends, and new architecture with more powerful and flexible E/E architecture is required. Adaptive AUTOSAR, the new architecture was released to support these functions, and the 1st release of the AUTOSAR adaptive platform was done in March 2017.

Adaptive AUTOSAR architecture comes with a central application server, which assists in high-performance computing. Ethernet-based ECUs in this system support real-time functionalities. Adaptive AUTOSAR is scalable and has dynamic architecture, in which applications can be updated over the vehicle’s lifecycle. To support modular and scalable system design, the adaptive platform organizes services and components into functional clusters, grouping related functionalities for efficient management and deployment. It enables OEMs to deploy high-tech software features in a vehicle and update them over-the-air whenever required.

AUTOSAR adaptive architecture supports all the futuristic automotive applications like infotainment, v2x, predictive maintenance, automotive apps, ADAS functions with a camera, RADAR and LIDAR sensors, map updates, electrification, and more.

Benefits of AUTOSAR

Adopting the AUTOSAR standard brings a wide range of benefits to automotive manufacturers and suppliers. One of the most significant advantages is the ability to develop scalable and portable software components, which can be reused across different vehicle models and hardware platforms. This standardization reduces development costs and accelerates time-to-market for new features. AUTOSAR also supports hardware-independent development, allowing software teams to design and test application software without being tied to specific hardware. This flexibility is crucial for integrating complex functions such as autonomous driving and advanced safety systems. By providing a robust and reliable software architecture, the AUTOSAR standard enhances the overall efficiency, safety, and innovation of automotive software development, enabling the industry to keep pace with rapidly evolving technology.

Future of AUTOSAR

Looking ahead, AUTOSAR is set to play an even more pivotal role in the future of automotive software development. As the industry moves toward greater levels of autonomous driving, electrification, and vehicle connectivity, the need for standardized software platforms and high-performance computing will continue to grow. The AUTOSAR partnership remains committed to evolving the standard, ensuring it meets the emerging technical and functional requirements of next-generation vehicles. By offering a flexible, scalable, and reliable software platform, AUTOSAR empowers manufacturers and suppliers to develop more sophisticated, efficient, and safe automotive systems. This ongoing innovation will help shape the future of mobility, deliver enhanced driving experiences, and support the transition to smarter, more connected vehicles worldwide.

Why eInfochips for AUTOSAR Services?

eInfochips (An Arrow Company) as an associate partner of AUTOSAR, assists automotive OEMs and tier 1 suppliers in many AUTOSAR related solutions like development, integration, and validation of AUTOSAR basic software modules, integration of AUTOSAR stack software from tool suppliers, upgrading platform software to new AUTOSAR versions as per specifications and more. Know more on eInfochips Automotive Engineering Services and Solutions.