VHAL Host Emulator

This is a collection of python modules as tools for VHAL development.

vhal_emulator.py

This allow you to create script to interate with the Vehicle HAL in an AAOS device from a host.

  • It sends and receives messages to/from the Vehicle HAL via port forwarding over ADB to communicate with the AAOS device.
  • On the device side, VHAL module VehicleService creates VehicleEmulator to setup SocketComm to serve the requests.
    • hardware/interfaces/automotive/vehicle/2.0/default/VehicleService.cpp
    • hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/VehicleEmulator.cpp
    • hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/SocketComm.cpp
  • vhal_emulator_test.py tests the Vehicle HAL via adb socket.
    • Note: This may outdated becuase there is no dedicated resrouce. Contribution is welcome.

vhal_const_generate.py

This generates vhal_consts_2_0.py to update definitions for property ID, value type, zone, etc. from the types.hal. Run this script whenever types.hal is changed.

  • Must re-generate when the types.hal file changes.
packages/services/Car/tools/emulator/vhal_const_generate.py
  • hardware/interfaces/automotive/vehicle/2.0/types.hal

VehicleHalProto_pb2.py

This defines message interface to VHAL Emulator from VehicleHalProto.proto.

  • Must re-generate whenever the proto file changes.
  • Generated from hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto/VehicleHalProto.proto
protoDir=$ANDROID_BUILD_TOP/hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto
outDir=$ANDROID_BUILD_TOP/packages/services/Car/tools/emulator
# or protoc if perferred
aprotoc -I=$protoDir --python_out=$outDir $protoDir/VehicleHalProto.proto

  • It requires Protocol Buffers. You may build one from Android, e.g.
. build/envsetup.sh
lunch sdk_gcar_x86-userdebug
m aprotoc -j16

OBD2 Diagnostic Injector

These scripts are useful for testing the Diagnostics API

diagnostic_builder.py

  • Helper class used by diagnostic_injector.py
  • Stores diagnostic sensor values and bitmasks
  • VehiclePropValue-compatible

diagnostic_injector.py

  • Deserializes JSON into diagnostic events
  • Sends over HAL Emulator Interface
  • Diagnostic JSON Format example: diagjson.example
./diagnostic_injector.py ./diagjson.example

Python GUI Example

gui.py is an example to create an GUI to set the property.

  • packages/services/Car/tools/emulator/gui.py
  • GUI runs on host machine (PyQt4-based widgets)
  • Drives VHAL on target
    • Works only with default VHAL
    • Interactions generate SET messages
  • Supports bench testing of apps
  • Easy to add support for more properties