前言
1、Google官网上是这样介绍汽车架构的。
- Car App：包括OEM和第三方开发的App
- Car API：内有包含 CarSensorManager 在内的 API。位于 /platform/packages/services/Car/car-lib。
- CarService：系统中与车相关的服务，位于 /platform/packages/services/Car/目录。
- 车载 HAL：用于定义 OEM 可以实现的车辆属性的接口。包含属性元数据（例如，车辆属性是否为 int 以及允许使用哪些更改模式）。位于 hardware/libhardware/include/hardware/vehicle.h。如需了解基本参考实现，请参阅 hardware/libhardware/modules/vehicle/。
2、 Framework CarService
1、Android O/P为Automotive场景提供了一系列的服务，这些服务统被称为CarService。它们与HAL层的VehicleHAL通信，进而通过车载总线(例如CAN总线)与车身进行通讯，同时它们还为应用层的APP提供接口，从而让APP能够实现对车身的控制与状态的显示。
- Car***Manage位于packages/services/Car/car-lib/src/android/car/hardware目录，
- Car***Service位于packages/services/Car/service/src/com/android/car目录。
一、目录结构
1、CarService主要位于packages/services/Car/目录。
├── Android.mk
├── apicheck.mk
├── apicheck_msg_current.txt
├── apicheck_msg_last.txt
├── car-cluster-logging-renderer //LoggingClusterRenderingService继承InstrumentClusterRenderingService
├── car-default-input-service //按键消息处理
├── car-lib //提供给汽车App特有的接口，许多定制的模块都在这里实现，包括Sensor,HVAC,Cabin,ActiveParkingAssiance,Diagnostic,Vendor等
├── car-maps-placeholder //地图软件相关
├── car_product //系统编译相关
├── car-support-lib //android.support.car
├── car-systemtest-lib //系统测试相关
├── car-usb-handler //开机自启，用于管理车机USB
├── CleanSpec.mk
├── evs
├── obd2-lib
├── PREUPLOAD.cfg
├── procfs-inspector
├── service //com.android.car是一个后台运行的组件，可以长时间运行并且不需要和用户去交互的，这里即使应用被销毁，它也可以正常工作
├── tests
├── tools //是一系列的工具，要提到的是里面的emulator，测试需要用到的。python写的，通过adb可以连接vehicleHal的工具，用于模拟测试
├── TrustAgent
└── vehicle-hal-support-lib
2、Car APP
1、Car APP的相关源码位于packages/apps/Car/目录，其中packages/services/Car/car_product/build/car.mk里面决定了需要编译哪些相关apk（system/priv-app）。
packages/services/Car/car_product/build/car.mk
# Common make file for all car builds
PRODUCT_PUBLIC_SEPOLICY_DIRS += packages/services/Car/car_product/sepolicy/public
PRODUCT_PRIVATE_SEPOLICY_DIRS += packages/services/Car/car_product/sepolicy/private
PRODUCT_PACKAGES += \
Bluetooth \
CarActivityResolver \
CarDeveloperOptions \
CarSettingsIntelligence \
CarManagedProvisioning \
OneTimeInitializer \
CarProvision \
StatementService \
SystemUpdater
PRODUCT_PACKAGES += \
clatd \
pppd \
screenrecord
# This is for testing
ifneq (,$(filter userdebug eng, $(TARGET_BUILD_VARIANT)))
PRODUCT_PACKAGES += \
DefaultStorageMonitoringCompanionApp \
EmbeddedKitchenSinkApp \
GarageModeTestApp \
ExperimentalCarService \
BugReportApp \
NetworkPreferenceApp \
SampleCustomInputService \
AdasLocationTestApp \
curl \
# SEPolicy for test apps / services
BOARD_SEPOLICY_DIRS += packages/services/Car/car_product/sepolicy/test
endif
# ClusterOsDouble is the testing app to test Cluster2 framework and it can handle Cluster VHAL
# and do some Cluster OS role.
ifeq ($(ENABLE_CLUSTER_OS_DOUBLE), true)
PRODUCT_PACKAGES += ClusterHomeSample ClusterOsDouble
else
# DirectRenderingCluster is the sample app for the old Cluster framework.
PRODUCT_PACKAGES += DirectRenderingCluster
endif # ENABLE_CLUSTER_OS_DOUBLE
PRODUCT_COPY_FILES += \
frameworks/av/media/libeffects/data/audio_effects.conf:system/etc/audio_effects.conf
PRODUCT_PROPERTY_OVERRIDES += \
persist.bluetooth.enablenewavrcp=false \
ro.carrier=unknown
PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
config.disable_systemtextclassifier=true
###
### Suggested values for multi-user properties - can be overridden
###
# Enable headless system user mode
PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
ro.fw.mu.headless_system_user?=true
# Enable user pre-creation
PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
android.car.number_pre_created_users?=1 \
android.car.number_pre_created_guests?=1
# Enable User HAL integration
# NOTE: when set to true, VHAL must also implement the user-related properties,
# otherwise CarService will ignore it
PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
android.car.user_hal_enabled?=true
### end of multi-user properties ###
# Overlay for Google network and fused location providers
$(call inherit-product, device/sample/products/location_overlay.mk)
$(call inherit-product-if-exists, frameworks/webview/chromium/chromium.mk)
$(call inherit-product, packages/services/Car/car_product/build/car_base.mk)
# Overrides
PRODUCT_BRAND := generic
PRODUCT_DEVICE := generic
PRODUCT_NAME := generic_car_no_telephony
PRODUCT_IS_AUTOMOTIVE := true
PRODUCT_PROPERTY_OVERRIDES := \
ro.config.ringtone=Girtab.ogg \
ro.config.notification_sound=Tethys.ogg \
ro.config.alarm_alert=Oxygen.ogg \
$(PRODUCT_PROPERTY_OVERRIDES) \
PRODUCT_PROPERTY_OVERRIDES += \
keyguard.no_require_sim=true
# TODO(b/205189147): Remove the following change after the proper fix is landed.
# Uses the local KeyGuard animation to resolve TaskView misalignment issue after display-on.
PRODUCT_SYSTEM_PROPERTIES += \
persist.wm.enable_remote_keyguard_animation=0
# Automotive specific packages
PRODUCT_PACKAGES += \
CarFrameworkPackageStubs \
CarService \
CarShell \
CarDialerApp \
CarRadioApp \
OverviewApp \
CarSystemUI \
LocalMediaPlayer \
CarMediaApp \
CarMessengerApp \
CarHTMLViewer \
CarMapsPlaceholder \
CarLatinIME \
CarSettings \
CarUsbHandler \
android.car \
car-frameworks-service \
com.android.car.procfsinspector \
libcar-framework-service-jni \
ScriptExecutor \
# RROs
PRODUCT_PACKAGES += \
CarPermissionControllerRRO \
# System Server components
# Order is important: if X depends on Y, then Y should precede X on the list.
PRODUCT_SYSTEM_SERVER_JARS += car-frameworks-service
# TODO: make the order optimal by appending 'car-frameworks-service' at the end
# after its dependency 'services'. Currently the order is violated because this
# makefile is included before AOSP makefile.
PRODUCT_BROKEN_SUBOPTIMAL_ORDER_OF_SYSTEM_SERVER_JARS := true
# Boot animation
PRODUCT_COPY_FILES += \
packages/services/Car/car_product/bootanimations/bootanimation-832.zip:system/media/bootanimation.zip
PRODUCT_LOCALES := \
en_US \
af_ZA \
am_ET \
ar_EG ar_XB \
as_IN \
az_AZ \
be_BY \
bg_BG \
bn_BD \
bs_BA \
ca_ES \
cs_CZ \
da_DK \
de_DE \
el_GR \
en_AU en_CA en_GB en_IN en_XA \
es_ES es_US \
et_EE \
eu_ES \
fa_IR \
fi_FI \
fil_PH \
fr_CA fr_FR \
gl_ES \
gu_IN \
hi_IN \
hr_HR \
hu_HU \
hy_AM \
id_ID \
is_IS \
it_IT \
iw_IL \
ja_JP \
ka_GE \
kk_KZ \
km_KH km_MH \
kn_IN \
ko_KR \
ky_KG \
lo_LA \
lv_LV \
lt_LT \
mk_MK \
ml_IN \
mn_MN \
mr_IN \
ms_MY \
my_MM \
ne_NP \
nl_NL \
no_NO \
or_IN \
pa_IN \
pl_PL \
pt_BR pt_PT \
ro_RO \
ru_RU \
si_LK \
sk_SK \
sl_SI \
sq_AL \
sr_RS \
sv_SE \
sw_TZ \
ta_IN \
te_IN \
th_TH \
tr_TR \
uk_UA \
ur_PK \
uz_UZ \
vi_VN \
zh_CN zh_HK zh_TW \
zu_ZA
PRODUCT_BOOT_JARS += \
android.car
PRODUCT_HIDDENAPI_STUBS := \
android.car-stubs-dex
PRODUCT_HIDDENAPI_STUBS_SYSTEM := \
android.car-system-stubs-dex
PRODUCT_HIDDENAPI_STUBS_TEST := \
android.car-test-stubs-dex
# Disable Prime Shader Cache in SurfaceFlinger to make it available faster
PRODUCT_PROPERTY_OVERRIDES += \
service.sf.prime_shader_cache=0