This directory stores the libraries useful for implementing vendor AIDL VHAL V4. This directory also stores a reference fake implementation for AIDL VHAL V4.
Stores the default vehicle property configurations for reference vehicle HAL. Vendor implementation could copy this library but must update the configuration to meet their own requirements, e.g. enable or disable certain properties or update the initial value for certain properties.
Contains libraries used specifically for the fake reference VHAL implementation. These libraries are for test only and must not be directly used for vendor VHAL implementation.
These libraries contain test-spcific logic and must not run directly on a real vehicle.
Stores code for GRPC based VHAL implementation.
The GRPC based VHAL implementation delegates most of the VHAL logic to a VHAL proxy server running remotely. For example, the server may run in a separate Android (maybe not AAOS) VM or a non-Android machine running in the same ethernet.
This is used in AAOS cuttlefish, where the VHAL proxy server is running on the host machine with AAOS running in a VM.
The GRPC VHAL uses DefaultVehicleHal, but with a special IVehicleHardware implementation: GRPCVehicleHardware. The GRPCVehicleHardware is a thin proxy layer that forwards all requests to a GRPC server (GRPCVehicleProxyServer).
The supported communication channels between GRPC VHAL and the GRPC Vehicle proxy server are Ethernet or Vsock.
Note that VHAL must be ready early on during the boot so the communciation channel setup step must happen very early before VHAL registers itself.
Defines an interface IVehicleHardware.h which vendor must implement for vehicle-specific logic if they want to follow our reference VHAL design.
Stores Some protobuf files translated from AIDL VHAL interface types. These files are used in GRPC VHAL implementation.
Defines a library VehicleHalUtils which provides useful utility functions for VHAL implementation. Vendor VHAL could use this library.
Defines a library DefaultVehicleHal which provides generic logic for all VHAL implementations (including reference VHAL). Vendor VHAL implementation could use this library, along with their own implementation for IVehicleHardware interface.
Also defines a binary android.hardware.automotive.vehicle@V4-default-service which is the reference VHAL implementation. It implements IVehicle.aidl interface. It uses DefaultVehicleHal, along with FakeVehicleHardware (in fake_impl). It simulates the vehicle bus interaction by using an in-memory map. Meaning that all properties (except for some special ones) are just written into a hash map and read from a hash map without relying on any hardware. As a result, the reference implementation can run on emulator or any host environment.
Vendor must not directly use the reference implementation for a real vehicle.