Vehicle Hardware Abstraction Layer (VHAL)
The Vehicle Hardware Abstraction Layer (VHAL) is the defined interface through which Android Automotive OS represents selected vehicle signals and functions as software properties. It separates the Android framework from manufacturer-specific control units, networks, and signal encodings.
How it works
A property can represent information or a controllable function, with metadata describing its data type, allowed access, update behavior, and supported areas. Software can read, write, or subscribe to permitted properties through the framework instead of implementing a different low-level vehicle-network connection for every model.
The manufacturer implements the vehicle side and decides which supported properties are exposed. The AOSP documentation describes the VHAL as a property-based interface and requires new implementations to use its AIDL form. Android Open Source Project: Vehicle HAL
What it does not mean
VHAL does not make every vehicle function available to every app. Android permissions, system services, gateways, validation, and the vehicle's safety architecture still restrict access. It is an abstraction boundary, not a bypass around safety or cybersecurity controls.
VHAL is specific terminology for Android Automotive OS; other embedded platforms can use different abstraction layers for the same architectural purpose.
Learn more
See Infotainment software platforms and AI for the relationship between hardware, operating systems, vehicle gateways, applications, and security domains.