Android Automotive(四) Vehicle Property
Android Automotive(四) Vehicle Property
在介绍CarService之前,先介绍一下Vehicle Property(车辆属性),车辆属性是Android Automotive 中最重要的内容之一,使用它来传递车辆上的一些重要信息。
车辆属性是硬件抽象层定义的汽车设备制造商可以实现的属性,并会包含属性元数据(例如,属性是否为 int 以及允许使用哪些更改模式)。Vehicle HAL 提供接口对车辆属性进行访问(读取、写入、订阅)。
车辆属性使用HIDL语言定义,代码位于hardware/interfaces/automotive/vehicle/2.0/types.hal
中。
车辆属性可以是只读、只写、也可以是读写。每个车辆属性都由一个int32
键唯一标识,且具有预定义的数据类型。区域属性可能具有多个值,具体取决于属性支持区域的数量
车辆属性的定义是由四个整型值做或运算取得的。它们描述了车辆属性的ID、分组、类型和区域。
INFO_VIN = (0x0100| VehiclePropertyGroup:SYSTEM| VehiclePropertyType:STRING| VehicleArea:GLOBAL)
除了定义所需的必须属性,车辆属性的额外信息以注释的形式标记在文件中。包括车辆属性的变化类型、读写性、单位、取值的数据结构等等。
/*** VIN of vehicle** @change_mode VehiclePropertyChangeMode:STATIC* @access VehiclePropertyAccess:READ*/
INFO_VIN =
具体如下
注释 | 描述 | 类型 |
---|---|---|
@change_mode | 变化模式 |
VehiclePropertyChangeMode STATIC 静态 ON_CHANGE 变化 CONTINUOUS 持续 |
@access | 读写性质 |
VehiclePropertyAccess READ 只读 WRITE 只写 READ_WRITE 读写 |
@unit | 单位 | VehicleUnit |
@data_enum | 数据结构 | |
@since | 增加的版本 |
属性ID
是一个int数值,通常是4位16进制,占半个字节。在车辆属性中使用“4567”后四位表示属性ID,如0x0000****
。通常省略高位0,写成0x****
的形式。
属性分组
分组表示了车辆属性的来源,区分是原生属性还是扩展属性。原生属性是指AOSP定义的属性,扩展属性是指OEM厂商自己定义增加的属性。在车辆属性中使用第0位占位0x*000000。
//types.hal中定义
enum VehiclePropertyGroup : int32_t {/*** Properties declared in AOSP must have this flag.*/SYSTEM = 0x10000000, //268435456/*** Properties declared by vendors must have this flag.*/VENDOR = 0x20000000, //536870912MASK = 0xf0000000, //-268435456
};
- SYSTEM:Google原生属性定义使用
- VENDOR:OME自定义属性使用
属性 | 十六进制 | 十进制 |
---|---|---|
SYSTEM | 0x10000000 | 268435456 |
VENDOR | 0x20000000 | 536870912 |
扩展属性必须使用VENDOR声明
属性类型
表示车辆属性对应值的数据类型,占0x00**0000第“23”位。
目前支持的数据类型如下
- STRING
- BOOLEAN
- INT32
- INT32_VEC (INT32[])
- INT64
- INT64_VEC (INT64[])
- FLOAT
- FLOAT_VEC (FLOAT[])
- BYTES
//types.hal中定义
/*** Enumerates supported data type for VehicleProperty.** Used to create property ID in VehicleProperty enum.*/
enum VehiclePropertyType : int32_t {STRING = 0x00100000,BOOLEAN = 0x00200000,INT32 = 0x00400000,INT32_VEC = 0x00410000,INT64 = 0x00500000,INT64_VEC = 0x00510000,FLOAT = 0x00600000,FLOAT_VEC = 0x00610000,BYTES = 0x00700000,/*** Any combination of scalar or vector types. The exact format must be* provided in the description of the property.** For vendor MIXED type properties, configArray needs to be formatted in this* structure.* configArray[0], 1 indicates the property has a String value* configArray[1], 1 indicates the property has a Boolean value .* configArray[2], 1 indicates the property has an Integer value.* configArray[3], the number indicates the size of Integer[] in the property.* configArray[4], 1 indicates the property has a Long value.* configArray[5], the number indicates the size of Long[] in the property.* configArray[6], 1 indicates the property has a Float value.* configArray[7], the number indicates the size of Float[] in the property.* configArray[8], the number indicates the size of byte[] in the property.* For example:* {@code configArray = {1, 1, 1, 3, 0, 0, 0, 0, 0}} indicates the property has* a String value, a Boolean value, an Integer value and an array with 3 integers.*/MIXED = 0x00e00000,MASK = 0x00ff0000
};
属性 | 十六进制 | 十进制 |
---|---|---|
STRING | 0x00100000 | 1048576 |
BOOLEAN | 0x00200000 | 2097152 |
INT32 | 0x00400000 | 4194304 |
INT32_VEC | 0x00410000 | 4259840 |
INT64 | 0x00500000 | 5242880 |
INT64_VEC | 0x00510000 | 5308416 |
FLOAT | 0x00600000 | 6291456 |
FLOAT_VEC | 0x00610000 | 6356992 |
BYTES | 0x00700000 | 7340032 |
MIXED | 0x00e00000 | 14680064 |
属性区域
属性区域定义了车辆属性归属车辆的哪一个模块,比如门或者窗。占位0x0*000000,第1位。
Android P 删除了ZONE区域,新增WHEEL区域。
每个区域属性都必须使用预定义的区域类型。每种区域类型都有一组在区域类型的枚举中定义的位标记。
//types.hal中定义
/*** Vehicle Areas* Used to construct property IDs in the VehicleProperty enum.** Some properties may be associated with particular vehicle areas. For* example, VehicleProperty:DOOR_LOCK property must be associated with* particular door, thus this property must be marked with* VehicleArea:DOOR flag.** Other properties may not be associated with particular vehicle area.* These kinds of properties must have VehicleArea:GLOBAL flag.** [Definition] Area: An area represents a unique element of an AreaType.* For instance, if AreaType is WINDOW, then an area may be FRONT_WINDSHIELD.** [Definition] AreaID: An AreaID is a combination of one or more areas,* and is represented using a bitmask of Area enums. Different AreaTypes may* not be mixed in a single AreaID. For instance, a window area cannot be* combined with a seat area in an AreaID.** Rules for mapping a zoned property to AreaIDs:* - A property must be mapped to an array of AreaIDs that are impacted when* the property value changes.* - Each element in the array must represent an AreaID, in which the* property value can only be changed together in all the areas within* the AreaID and never independently. That is, when the property value* changes in one of the areas in an AreaID in the array, then it must* automatically change in all other areas in the AreaID.* - The property value must be independently controllable in any two* different AreaIDs in the array.* - An area must only appear once in the array of AreaIDs. That is, an* area must only be part of a single AreaID in the array.** [Definition] Global Property: A property that applies to the entire car* and is not associated with a specific area. For example, FUEL_LEVEL,* HVAC_STEERING_WHEEL_HEAT.** Rules for mapping a global property to AreaIDs:* - A global property must not be mapped to AreaIDs.
*/
enum VehicleArea : int32_t {GLOBAL = 0x01000000,/** WINDOW maps to enum VehicleAreaWindow *///ZONE = 0x02000000, //android P开始删除WINDOW = 0x03000000,/** MIRROR maps to enum VehicleAreaMirror */MIRROR = 0x04000000,/** SEAT maps to enum VehicleAreaSeat */SEAT = 0x05000000,/** DOOR maps to enum VehicleAreaDoor */DOOR = 0x06000000,/** WHEEL maps to enum VehicleAreaWheel */WHEEL = 0x07000000,MASK = 0x0f000000,
};
属性 | 十六进制 | 十进制 |
---|---|---|
GLOBAL | 0x01000000 | 16777216 |
ZONE | 0x02000000 | 33554432 |
WINDOW | 0x03000000 | 50331648 |
MIRROR | 0x04000000 | 67108864 |
SEAT | 0x05000000 | 83886080 |
DOOR | 0x06000000 | 100663296 |
WHEEL | 0x07000000 | 117440512 |
GLOBAL
此属性是单一实例,不具备多个区域。
ZONE
用于空调并将汽车划分为物理区域。
在Android P版本删除。使用枚举类
VehicleAreaZone
。Android P 开始删除此属性
//types.hal中定义
/*** Various zones in the car.** Zones are used for Air Conditioning purposes and divide the car into physical* area zones.*/
enum VehicleAreaZone : int32_t {ROW_1_LEFT = 0x00000001,ROW_1_CENTER = 0x00000002,ROW_1_RIGHT = 0x00000004,ROW_1 = 0x00000008,ROW_2_LEFT = 0x00000010,ROW_2_CENTER = 0x00000020,ROW_2_RIGHT = 0x00000040,ROW_2 = 0x00000080,ROW_3_LEFT = 0x00000100,ROW_3_CENTER = 0x00000200,ROW_3_RIGHT = 0x00000400,ROW_3 = 0x00000800,ROW_4_LEFT = 0x00001000,ROW_4_CENTER = 0x00002000,ROW_4_RIGHT = 0x00004000,ROW_4 = 0x00008000,WHOLE_CABIN = 0x80000000,
};
WINDOW
基于车窗的区域。使用枚举类VehicleAreaWindow
- FRONT_WINDSHIELD 前挡风玻璃
- REAR_WINDSHIELD 后挡风玻璃
- ROW_1_LEFT 第一排左侧车窗
- ROW_1_RIGHT 第一排右侧车窗
- ROW_2_LEFT 第二排左侧车窗
- ROW_2_RIGHT 第二排右侧车窗
- ROW_3_LEFT 第三排左侧车窗
- ROW_3_RIGHT 第三排右侧车窗
- ROOF_TOP_1 天窗1
- ROOF_TOP_2 天窗2
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Various windshields/windows in the car.*/
enum VehicleAreaWindow : int32_t {FRONT_WINDSHIELD = 0x00000001,REAR_WINDSHIELD = 0x00000002,ROW_1_LEFT = 0x00000010,ROW_1_RIGHT = 0x00000040,ROW_2_LEFT = 0x00000100,ROW_2_RIGHT = 0x00000400,ROW_3_LEFT = 0x00001000,ROW_3_RIGHT = 0x00004000,ROOF_TOP_1 = 0x00010000,ROOF_TOP_2 = 0x00020000,};
属性 | 十六进制 | 十进制 |
---|---|---|
FRONT_WINDSHIELD | 0x00000001 | 1 |
REAR_WINDSHIELD | 0x00000002 | 2 |
ROW_1_LEFT | 0x00000010 | 16 |
ROW_1_RIGHT | 0x00000040 | 64 |
ROW_2_LEFT | 0x00000100 | 256 |
ROW_2_RIGHT | 0x00000400 | 1024 |
ROW_3_LEFT | 0x00001000 | 4096 |
ROW_3_RIGHT | 0x00004000 | 16384 |
ROOF_TOP_1 | 0x00010000 | 65536 |
ROOF_TOP_2 | 0x00020000 | 131072 |
MIRROR
基于车镜的区域。使用枚举类VehicleAreaMirror
- DRIVER_LEFT 左后视镜
- DRIVER_RIGHT 右后视镜
- DRIVER_CENTER 中央后视镜
// hardware/interfaces/automotive/vehicle/2.0/types.hal
enum VehicleAreaMirror : int32_t {DRIVER_LEFT = 0x00000001,DRIVER_RIGHT = 0x00000002,DRIVER_CENTER = 0x00000004,
};
属性 | 十六进制 | 十进制 |
---|---|---|
DRIVER_LEFT | 0x00000001 | 1 |
DRIVER_RIGHT | 0x00000002 | 2 |
DRIVER_CENTER | 0x00000004 | 4 |
SEAT
基于座椅的区域,使用枚举类VehicleAreaSeat
- ROW_1_LEFT 第一排左侧
- ROW_1_CENTER 第一排中间
- ROW_1_RIGHT 第一排右侧
- ROW_2_LEFT 第二排左侧
- ROW_2_CENTER 第二排中间
- ROW_2_RIGHT 第二排右侧
- ROW_3_LEFT 第三排左侧
- ROW_3_CENTER 第三排中间
- ROW_3_RIGHT 第三排右侧
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Various Seats in the car.*/
enum VehicleAreaSeat : int32_t {ROW_1_LEFT = 0x0001,ROW_1_CENTER = 0x0002,ROW_1_RIGHT = 0x0004,ROW_2_LEFT = 0x0010,ROW_2_CENTER = 0x0020,ROW_2_RIGHT = 0x0040,ROW_3_LEFT = 0x0100,ROW_3_CENTER = 0x0200,ROW_3_RIGHT = 0x0400
};
属性 | 十六进制 | 十进制 |
---|---|---|
ROW_1_LEFT | 0x0001 | 1 |
ROW_1_CENTER | 0x0002 | 2 |
ROW_1_RIGHT | 0x0004 | 4 |
ROW_2_LEFT | 0x0010 | 16 |
ROW_2_CENTER | 0x0020 | 32 |
ROW_2_RIGHT | 0x0040 | 64 |
ROW_3_LEFT | 0x0100 | 256 |
ROW_3_CENTER | 0x0200 | 512 |
ROW_3_RIGHT | 0x0400 | 1024 |
DOOR
基于车门的区域。使用枚举类VehicleAreaDoor
- ROW_1_LEFT 第一排左侧门
- ROW_1_RIGHT 第一排右侧门
- ROW_2_LEFT 第二排左侧门
- ROW_2_RIGHT 第二排右侧门
- ROW_3_LEFT 第三排左侧门
- ROW_3_RIGHT 第三排右侧门
- HOOD 前车厢门
- REAR 后车厢门
// hardware/interfaces/automotive/vehicle/2.0/types.hal
enum VehicleAreaDoor : int32_t {ROW_1_LEFT = 0x00000001,ROW_1_RIGHT = 0x00000004,ROW_2_LEFT = 0x00000010,ROW_2_RIGHT = 0x00000040,ROW_3_LEFT = 0x00000100,ROW_3_RIGHT = 0x00000400,HOOD = 0x10000000,REAR = 0x20000000,
};
属性 | 十六进制 | 十进制 |
---|---|---|
ROW_1_LEFT | 0x00000001 | 1 |
ROW_1_RIGHT | 0x00000004 | 4 |
ROW_2_LEFT | 0x00000010 | 16 |
ROW_2_RIGHT | 0x00000040 | 64 |
ROW_3_LEFT | 0x00000100 | 256 |
ROW_3_RIGHT | 0x00000400 | 1024 |
HOOD | 0x10000000 | 268435456 |
REAR | 0x20000000 | 536870912 |
WHEEL
基于车轮的区域。使用枚举类VehicleAreaWheel
- UNKNOWN 未知
- LEFT_FRONT 左前轮胎
- RIGHT_FRONT 右前轮胎
- LEFT_REAR 左后轮胎
- RIGHT_REAR 右后轮胎
// hardware/interfaces/automotive/vehicle/2.0/types.hal
enum VehicleAreaWheel : int32_t {UNKNOWN = 0x0,LEFT_FRONT = 0x1,RIGHT_FRONT = 0x2,LEFT_REAR = 0x4,RIGHT_REAR = 0x8,
};
属性 | 十六进制 | 十进制 |
---|---|---|
UNKNOWN | 0x0 | 0 |
LEFT_FRONT | 0x1 | 1 |
RIGHT_FRONT | 0x2 | 2 |
LEFT_REAR | 0x4 | 4 |
RIGHT_REAR | 0x8 | 8 |
每个区域属性都必须使用预定义的区域类型。每种区域类型都有一组在区域类型的枚举中定义的位标记
区域 ID
区域属性通过区域 ID 进行处理。每个区域属性都可以支持一个或多个区域 ID。区域 ID 由其各自枚举中的一个或多个标记组成。例如,使用 VehicleAreaSeat
的属性可能会使用以下区域 ID:
ROW_1_LEFT | ROW_1_RIGHT
区域 ID 适用于两个前排座椅。ROW_2_LEFT
仅适用于左后座椅。ROW_2_RIGHT
仅适用于右后座椅。
属性操作
车辆属性的可见性标识该属性是否只读,只写,读写。在types.hal
中以注释@access
的形式出现
如:@access VehiclePropertyAccess::READ_WRITE
- NONE 不可读不可写
- READ 只读
- WRITE 只写
- READ_WRITE 读写
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Property config defines the capabilities of it. User of the API* must first get the property config to understand the output from get()* commands and also to ensure that set() or events commands are in sync with* the expected output.*/
enum VehiclePropertyAccess : int32_t {NONE = 0x00,READ = 0x01,WRITE = 0x02,READ_WRITE = 0x03,
};
属性 | 说明 | Android版本 |
---|---|---|
NONE | 不可读不可写 | |
READ | 只读 | 8.0~ |
WRITE | 只写 | 8.0~ |
READ_WRITE | 读写 | 8.0~ |
属性 | 十六进制 | 十进制 |
---|---|---|
NONE | 0x00 | 0 |
READ | 0x01 | 1 |
WRITE | 0x02 | 2 |
READ_WRITE | 0x03 | 3 |
属性变化模式
属性的变化模式,在types.hal
中以注释@change_mode
的形式出现
如:@change_mode VehiclePropertyChangeMode::ON_CHANGE
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** This describes how value of property can change.*/
enum VehiclePropertyChangeMode : int32_t {/*** Property of this type must never be changed. Subscription is not supported* for these properties.*/STATIC = 0x00,/*** Property of this type must be reported when there is a change.* IVehicle#get call must return the current value.* Set operation for this property is assumed to be asynchronous. When the* property is read (using IVehicle#get) after IVehicle#set, it may still* return old value until underlying H/W backing this property has actually* changed the state. Once state is changed, the property must dispatch* changed value as event.*/ON_CHANGE = 0x01,/*** Property of this type change continuously and requires fixed rate of* sampling to retrieve the data.*/CONTINUOUS = 0x02,/*** Property of this type may be polled to get the current value.*/POLL = 0x03,/*** This is for property where change event must be sent only when the* value is set from external component. Normal value change must not trigger* event. For example, clock property can send change event only when it is* set, outside android, for case like user setting time or time getting* update. There is no need to send it per every value change.*/ON_SET = 0x04,
};
属性 | 说明 | Android版本 |
---|---|---|
STATIC | 决不能更改此类型的属性。不支持订阅这些属性 | 8.0~ |
ON_CHANGE | 发生改变时,必须报告此类型的属性。 IVehicle#get调用必须返回当前值。假如设置是异步的,当在IVehicle#set之后读取属性时,它可能返回旧值,直到此属性的底层H/W实际更改了状态。状态更改后,属性必须将更改的值作为事件分派。 | 8.0~ |
CONTINUOUS | 此种类型的属性不断变化,需要固定的采样率来检索数据。实现者可以选择在重大值更改时发送额外的通知。如车速 | 8.0~ |
POLL | 可以轮询此类型的属性以获取当前值 | 8.0 |
ON_SET | 变化时不需要一直上报,只有上层主动获取才上报,比如时间更新 | 8.0 |
POLL 和 ON_SET在Android P上被删除,不再使用
属性单位
某些属性的值需要配合国际单位来表示,比如车速的单位是米每秒(MILLIMETER)。
属性值的单位, 在types.hal
中以注释@unit
的形式出现,表示车辆属性表示含义的单位。
如:@unit VehicleUnit:YEAR
表示单位是年
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Units used for int or float type with no attached enum types.*/
enum VehicleUnit : int32_t {SHOULD_NOT_USE = 0x000,METER_PER_SEC = 0x01,RPM = 0x02,HERTZ = 0x03,PERCENTILE = 0x10,MILLIMETER = 0x20,METER = 0x21,KILOMETER = 0x23,MILE = 0x24,CELSIUS = 0x30,FAHRENHEIT = 0x31,KELVIN = 0x32,MILLILITER = 0x40,LITER = 0x41,/** deprecated. Use US_GALLON instead. */GALLON = 0x42,US_GALLON = 0x42,IMPERIAL_GALLON = 0x43,NANO_SECS = 0x50,SECS = 0x53,YEAR = 0x59,// Electrical UnitsWATT_HOUR = 0x60,MILLIAMPERE = 0x61,MILLIVOLT = 0x62,MILLIWATTS = 0x63,AMPERE_HOURS = 0x64,KILOWATT_HOUR = 0x65,KILOPASCAL = 0x70,PSI = 0x71,BAR = 0x72,DEGREES = 0x80,MILES_PER_HOUR = 0x90,KILOMETERS_PER_HOUR = 0x91,
};
- SHOULD_NOT_USE, 不使用
- METER_PER_SEC, 米每秒
- RPM, 转速
- HERTZ, 赫兹
- PERCENTILE, 百分比
- MILLIMETER, 毫米
- METER, 米
- KILOMETER, 千米,公里
- MILE, 英里
- CELSIUS, 摄氏度
- FAHRENHEIT, 华氏度
- KELVIN, 开尔文
- MILLILITER, 毫升
- LITER, 升
- US_GALLON, 美国加仑
- IMPERIAL_GALLON, 英制加仑
- NANO_SECS, 纳秒
- SECS, 秒
- YEAR, 年
- KILOPASCAL, 千帕
- WATT_HOUR, 瓦时
- MILLIAMPERE, 毫安
- MILLIVOLT, 毫伏
- MILLIWATTS, 毫瓦
- AMPERE_HOURS, 安倍小时
- KILOWATT_HOUR, 千瓦时
- PSI, 磅/平方英寸
- BAR, 巴 压强的单位
- DEGREES, 度
- MILES_PER_HOUR, 英里每小时
- KILOMETERS_PER_HOUR 公里每小时
属性数据结构
某些属性,将属性的可取值封装成一个对象,这样可以方便调用,比如VehicleGear
表示档位。
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Various gears which can be selected by user and chosen in system.*/
enum VehicleGear: int32_t {GEAR_NEUTRAL = 0x0001,GEAR_REVERSE = 0x0002,GEAR_PARK = 0x0004,GEAR_DRIVE = 0x0008,GEAR_LOW = 0x0010,GEAR_1 = 0x0010,GEAR_2 = 0x0020,GEAR_3 = 0x0040,GEAR_4 = 0x0080,GEAR_5 = 0x0100,GEAR_6 = 0x0200,GEAR_7 = 0x0400,GEAR_8 = 0x0800,GEAR_9 = 0x1000,
};
属性权限
属性的权限是Android在系统框架层增加的,只有声明权限的应用才可以访问相关的车辆属性。
属性的权限检测在CarService
中,配置在PropertyHalServiceIds.java
中使用,关联到各个车辆属性。
// packages/services/Car/service/src/com/android/car/hal/PropertyHalServiceIds.java
// default vendor permission
private static final int PERMISSION_CAR_VENDOR_DEFAULT = 0x00000000;// permissions for the property related with window
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_WINDOW = 0X00000001;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_WINDOW = 0x00000002;
// permissions for the property related with door
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_DOOR = 0x00000003;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_DOOR = 0x00000004;
// permissions for the property related with seat
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_SEAT = 0x00000005;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_SEAT = 0x00000006;
// permissions for the property related with mirror
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_MIRROR = 0x00000007;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_MIRROR = 0x00000008;// permissions for the property related with car's information
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_INFO = 0x00000009;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_INFO = 0x0000000A;
// permissions for the property related with car's engine
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_ENGINE = 0x0000000B;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_ENGINE = 0x0000000C;
// permissions for the property related with car's HVAC
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_HVAC = 0x0000000D;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_HVAC = 0x0000000E;
// permissions for the property related with car's light
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_LIGHT = 0x0000000F;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_LIGHT = 0x00000010;// permissions reserved for other vendor permission
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_1 = 0x00010000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_1 = 0x00011000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_2 = 0x00020000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_2 = 0x00021000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_3 = 0x00030000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_3 = 0x00031000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_4 = 0x00040000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_4 = 0x00041000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_5 = 0x00050000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_5 = 0x00051000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_6 = 0x00060000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_6 = 0x00061000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_7 = 0x00070000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_7 = 0x00071000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_8 = 0x00080000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_8 = 0x00081000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_9 = 0x00090000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_9 = 0x00091000;
private static final int PERMISSION_SET_CAR_VENDOR_CATEGORY_10 = 0x000A0000;
private static final int PERMISSION_GET_CAR_VENDOR_CATEGORY_10 = 0x000A1000;
// Not available for android
private static final int PERMISSION_CAR_VENDOR_NOT_ACCESSIBLE = 0xF0000000;
在HAL层定义
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Used by SUPPORT_CUSTOMIZE_VENDOR_PERMISSION to indicate the permission of vendor properties.*/
enum VehicleVendorPermission : int32_t {PERMISSION_DEFAULT = 0x00000000,// permissions for the property related with windowPERMISSION_SET_VENDOR_CATEGORY_WINDOW= 0X00000001,PERMISSION_GET_VENDOR_CATEGORY_WINDOW = 0x00000002,// permissions for the property related with doorPERMISSION_SET_VENDOR_CATEGORY_DOOR = 0x00000003,PERMISSION_GET_VENDOR_CATEGORY_DOOR = 0x00000004,// permissions for the property related with seatPERMISSION_SET_VENDOR_CATEGORY_SEAT = 0x00000005,PERMISSION_GET_VENDOR_CATEGORY_SEAT = 0x00000006,// permissions for the property related with mirrorPERMISSION_SET_VENDOR_CATEGORY_MIRROR= 0x00000007,PERMISSION_GET_VENDOR_CATEGORY_MIRROR = 0x00000008,// permissions for the property related with car's informationPERMISSION_SET_VENDOR_CATEGORY_INFO = 0x00000009,PERMISSION_GET_VENDOR_CATEGORY_INFO = 0x0000000A,// permissions for the property related with car's enginePERMISSION_SET_VENDOR_CATEGORY_ENGINE= 0x0000000B,PERMISSION_GET_VENDOR_CATEGORY_ENGINE = 0x0000000C,// permissions for the property related with car's HVACPERMISSION_SET_VENDOR_CATEGORY_HVAC = 0x0000000D,PERMISSION_GET_VENDOR_CATEGORY_HVAC = 0x0000000E,// permissions for the property related with car's lightPERMISSION_SET_VENDOR_CATEGORY_LIGHT = 0x0000000F,PERMISSION_GET_VENDOR_CATEGORY_LIGHT = 0x00000010,// permissions reserved for other vendor permissionPERMISSION_SET_VENDOR_CATEGORY_1 = 0x00010000,PERMISSION_GET_VENDOR_CATEGORY_1 = 0x00011000,PERMISSION_SET_VENDOR_CATEGORY_2 = 0x00020000,PERMISSION_GET_VENDOR_CATEGORY_2 = 0x00021000,PERMISSION_SET_VENDOR_CATEGORY_3 = 0x00030000,PERMISSION_GET_VENDOR_CATEGORY_3 = 0x00031000,PERMISSION_SET_VENDOR_CATEGORY_4 = 0x00040000,PERMISSION_GET_VENDOR_CATEGORY_4 = 0x00041000,PERMISSION_SET_VENDOR_CATEGORY_5 = 0x00050000,PERMISSION_GET_VENDOR_CATEGORY_5 = 0x00051000,PERMISSION_SET_VENDOR_CATEGORY_6 = 0x00060000,PERMISSION_GET_VENDOR_CATEGORY_6 = 0x00061000,PERMISSION_SET_VENDOR_CATEGORY_7 = 0x00070000,PERMISSION_GET_VENDOR_CATEGORY_7 = 0x00071000,PERMISSION_SET_VENDOR_CATEGORY_8 = 0x00080000,PERMISSION_GET_VENDOR_CATEGORY_8 = 0x00081000,PERMISSION_SET_VENDOR_CATEGORY_9 = 0x00090000,PERMISSION_GET_VENDOR_CATEGORY_9 = 0x00091000,PERMISSION_SET_VENDOR_CATEGORY_10 = 0x000A0000,PERMISSION_GET_VENDOR_CATEGORY_10 = 0x000A1000,// Indicate not available for android to access.PERMISSION_NOT_ACCESSIBLE = 0xF0000000
};
在Framework中VehicleVendorPermission定义了应用使用的权限字符串。
// packages/services/Car/car-lib/src/android/car/hardware/property/VehicleVendorPermission.java
// permissions for the property related with window
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_WINDOW ="android.car.permission.GET_CAR_VENDOR_CATEGORY_WINDOW";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_WINDOW ="android.car.permission.SET_CAR_VENDOR_CATEGORY_WINDOW";// permissions for the property related with door
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_DOOR ="android.car.permission.GET_CAR_VENDOR_CATEGORY_DOOR";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_DOOR ="android.car.permission.SET_CAR_VENDOR_CATEGORY_DOOR";// permissions for the property related with seat
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_SEAT ="android.car.permission.GET_CAR_VENDOR_CATEGORY_SEAT";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_SEAT ="android.car.permission.SET_CAR_VENDOR_CATEGORY_SEAT";// permissions for the property related with mirror
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_MIRROR ="android.car.permission.GET_CAR_VENDOR_CATEGORY_MIRROR";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_MIRROR ="android.car.permission.SET_CAR_VENDOR_CATEGORY_MIRROR";// permissions for the property related with car's information
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_INFO ="android.car.permission.GET_CAR_VENDOR_CATEGORY_INFO";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_INFO ="android.car.permission.SET_CAR_VENDOR_CATEGORY_INFO";// permissions for the property related with car's engine
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_ENGINE ="android.car.permission.GET_CAR_VENDOR_CATEGORY_ENGINE";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_ENGINE ="android.car.permission.SET_CAR_VENDOR_CATEGORY_ENGINE";// permissions for the property related with car's HVAC
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_HVAC ="android.car.permission.GET_CAR_VENDOR_CATEGORY_HVAC";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_HVAC ="android.car.permission.SET_CAR_VENDOR_CATEGORY_HVAC";// permissions for the property related with car's light
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_LIGHT ="android.car.permission.GET_CAR_VENDOR_CATEGORY_LIGHT";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_LIGHT ="android.car.permission.SET_CAR_VENDOR_CATEGORY_LIGHT";// permissions reserved for other vendor permission
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_1 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_1";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_1 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_1";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_2 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_2";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_2 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_2";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_3 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_3";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_3 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_3";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_4 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_4";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_4 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_4";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_5 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_5";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_5 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_5";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_6 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_6";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_6 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_6";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_7 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_7";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_7 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_7";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_8 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_8";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_8 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_8";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_9 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_9";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_9 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_9";
public static final String PERMISSION_GET_CAR_VENDOR_CATEGORY_10 ="android.car.permission.GET_CAR_VENDOR_CATEGORY_10";
public static final String PERMISSION_SET_CAR_VENDOR_CATEGORY_10 ="android.car.permission.SET_CAR_VENDOR_CATEGORY_10";
属性状态
每个属性值都随附一个 VehiclePropertyStatus
值。该值指示相应属性的当前状态:
AVAILABLE
属性可用,且值有效。UNAVAILABLE
属性值目前不可用。该值用于受支持属性的暂时停用的功能。ERROR
该属性有问题。
如果车辆不支持某个属性,则不应将其包含在 VHAL 中。您不得将属性状态永久性设置为 UNAVAILABLE
来表示不受支持的属性。
配置属性
在硬件抽象层会用一个VehiclePropConfig
结构体来维护车辆属性的配置。
// hardware/interfaces/automotive/vehicle/2.0/types.hal
struct VehiclePropConfig {/** Property identifier */int32_t prop;/*** Defines if the property is read or write or both.*/VehiclePropertyAccess access;/*** Defines the change mode of the property.*/VehiclePropertyChangeMode changeMode;/*** Contains per-area configuration.*/vec<VehicleAreaConfig> areaConfigs;/** Contains additional configuration parameters */vec<int32_t> configArray;/*** Some properties may require additional information passed over this* string. Most properties do not need to set this.*/string configString;/*** Min sample rate in Hz.* Must be defined for VehiclePropertyChangeMode::CONTINUOUS*/float minSampleRate;/*** Must be defined for VehiclePropertyChangeMode::CONTINUOUS* Max sample rate in Hz.*/float maxSampleRate;
};
- prop 属性ID
- access 属性读写权限
- changeMode 属性变化模式
- areaConfigs 属性每个区域的配置
- configArray 配置相关的数组
- configString 配置的描述
- minSampleRate 最小的变化频率,通知频率,变化模式必须定义为CONTINUOUS
- maxSampleRate 最大的变化频率,通知频率,变化模式必须定义为CONTINUOUS
字段 | 描述 |
---|---|
prop | 属性ID |
access | 属性读写权限 |
changeMode | 属性变化模式 |
areaConfigs | 属性每个区域的配置 |
configArray | 配置相关的数组 |
configString | 配置的描述 |
minSampleRate | 最小的变化频率,通知频率,变化模式必须定义为CONTINUOUS |
maxSampleRate | 最大的变化频率,通知频率,变化模式必须定义为CONTINUOUS |
在Android N上使用
vehicle_prop_config_t
进行配置使用
vehicle_prop_config_t
为每个属性提供配置信息。具体信息包括:
access
(r、w、rw)changeMode
(表示监视属性的方式:变化模式还是连续模式)areaConfigs
(areaId、最小值和最大值)configArray
(其他配置参数)configString
(以字符串的形式传递的其他信息)minSampleRate
、max_sample_rate
prop
(属性 ID、int)
属性取值
属性的取值,也就是属性所带的数据使用VehiclePropValue来维护。在types.hal中定义。
// hardware/interfaces/automotive/vehicle/2.0/types.hal
/*** Encapsulates the property name and the associated value. It* is used across various API calls to set values, get values or to register for* events.*/
struct VehiclePropValue {/** Time is elapsed nanoseconds since boot */int64_t timestamp;/*** Area type(s) for non-global property it must be one of the value from* VehicleArea* enums or 0 for global properties.*/int32_t areaId;/** Property identifier */int32_t prop;/** Status of the property */VehiclePropertyStatus status;/*** Contains value for a single property. Depending on property data type of* this property (VehiclePropetyType) one field of this structure must be filled in.*/struct RawValue {/*** This is used for properties of types VehiclePropertyType#INT* and VehiclePropertyType#INT_VEC*/vec<int32_t> int32Values;/*** This is used for properties of types VehiclePropertyType#FLOAT* and VehiclePropertyType#FLOAT_VEC*/vec<float> floatValues;/** This is used for properties of type VehiclePropertyType#INT64 */vec<int64_t> int64Values;/** This is used for properties of type VehiclePropertyType#BYTES */vec<uint8_t> bytes;/** This is used for properties of type VehiclePropertyType#STRING */string stringValue;};RawValue value;
};
字段` | 描述 |
---|---|
timestamp | 时间戳,标记属性更新的时间 |
areaId | 表示的区域 |
prop | 属性ID |
status | 属性的状态 |
value | 用RawValue来维护具体的属性值 |
int32Values | 维护整型数据的数组,布尔类型也是用此维护 |
int64Values | 维护长整型数据的数组 |
floatValues | 维护浮点型数据的数组 |
bytes | 维护字节型数据的数组 |
stringValue | 维护字符串类型 |
常量接口
前面我们知道HAL文件是使用HIDL语言定义,它在编译时,会生成C++和JAVA接口。
typs.hal
也是一样,里面定义的车辆属性会编译出系统框架层和硬件抽象层使用的接口。
编译产物
源码下automotive生成的文件如下:
代码路径:out/soong/.intermediates/hardware/interfaces/automotive/vehicle/2.0
out/soong/.intermediates/hardware/interfaces/automotive/vehicle/2.0
├── android.hardware.automotive.vehicle@2.0
│ ├── android_arm64_armv8-a_core_shared
│ │ └── android.hardware.automotive.vehicle@2.0.so
│ ├── android_arm64_armv8-a_core_static
│ │ ├── android.hardware.automotive.vehicle@2.0.a
│ │ └── obj
│ ├── android_arm_armv7-a-neon_cortex-a9_core_shared
│ │ └── android.hardware.automotive.vehicle@2.0.so
│ └── android_arm_armv7-a-neon_cortex-a9_core_static
│ ├── android.hardware.automotive.vehicle@2.0.a
│ └── obj
├── android.hardware.automotive.vehicle@2.0_genc++
│ └── gen
│ └── android
├── android.hardware.automotive.vehicle@2.0_genc++_headers
│ └── gen
│ └── android
├── android.hardware.automotive.vehicle-V2.0-java
│ └── android_common
│ ├── combined
│ ├── javac
│ ├── turbine
│ └── turbine-combined
└── android.hardware.automotive.vehicle-V2.0-java_gen_java└── gen└── android
hidl-gen
hidl-gen
时编译HIDL文件的一个工具
工具路径 out/host/linux-x86/bin/hidl-gen
,源代码路径 system/tools/hidl
使用说明
usage: hidl-gen [-p <root path>] -o <output path> -L <language> [-O <owner>] (-r <interface root>)+ [-v] [-d <depfile>] FQNAME...Process FQNAME, PACKAGE(.SUBPACKAGE)*@[0-9]+.[0-9]+(::TYPE)?, to create output.-h: Prints this menu.-L <language>: The following options are available:check : Parses the interface to see if valid but doesn't write any files.c++ : (internal) (deprecated) Generates C++ interface files for talking to HIDL interfaces.c++-headers : (internal) Generates C++ headers for interface files for talking to HIDL interfaces.c++-sources : (internal) Generates C++ sources for interface files for talking to HIDL interfaces.export-header : Generates a header file from @export enumerations to help maintain legacy code.c++-impl : Generates boilerplate implementation of a hidl interface in C++ (for convenience).c++-impl-headers: c++-impl but headers onlyc++-impl-sources: c++-impl but sources onlyc++-adapter : Takes a x.(y+n) interface and mocks an x.y interface.c++-adapter-headers: c++-adapter but helper headers onlyc++-adapter-sources: c++-adapter but helper sources onlyc++-adapter-main: c++-adapter but the adapter binary source onlyjava : (internal) Generates Java library for talking to HIDL interfaces in Java.java-constants : (internal) Like export-header but for Java (always created by -Lmakefile if @export exists).vts : (internal) Generates vts proto files for use in vtsd.makefile : (removed) Used to generate makefiles for -Ljava and -Ljava-constants.androidbp : (internal) Generates Soong bp files for -Lc++-headers, -Lc++-sources, -Ljava, -Ljava-constants, and -Lc++-adapter.androidbp-impl : Generates boilerplate bp files for implementation created with -Lc++-impl.hash : Prints hashes of interface in `current.txt` format to standard out.-O <owner>: The owner of the module for -Landroidbp(-impl)?.-o <output path>: Location to output files.-p <root path>: Android build root, defaults to $ANDROID_BUILD_TOP or pwd.-r <package:path root>: E.g., android.hardware:hardware/interfaces.-v: verbose output.-d <depfile>: location of depfile to write to.
hidl-gen
工具会将hal文件转换为相应的类文件, 例:
启动环境
. build/envsetup.sh
lunch
命令
./out/host/linux-x86/bin/hidl-gen -o ./demo -Ljava -randroid.hardware:hardware/interfaces -randroid.hidl:system/libhidl/transport android.hardware.automotive.vehicle@2.0
说明
-o: 生成文件的目录
-Lc+±headers: 生成c++ 头文件
-Ljava : 生成java文件
-r:指定包号和root路径
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