SUPPORTED_PROPERTY_IDS
What it is
(Deprecated) List of all supported property IDs.
A list of all supported property IDs (including this property). This property is required for HIDL VHAL to work with large amount of vehicle prop configs where the getAllPropConfigs payload exceeds the binder limitation. This issue is fixed in AIDL version using LargeParcelable in getAllPropConfigs, so this property is deprecated.
In HIDL VHAL implementation, if the amount of data returned in getAllPropConfigs exceeds the binder limitation, vendor must support this property and return all the supported property IDs. Car service will divide this list into smaller sub lists and use getPropConfigs([ids]) to query the sub lists. The results will be merged together in Car Service.
The config array for this property must contain one int element which is the number of configs per getPropConfigs request by Car Service. This number must be small enough so that each getPropConfigs payload will not exceed binder limitation, however, a smaller number will cause more requests, which increase overhead to fetch all the configs.
How the ID is built
A property ID is a 32-bit value packing four fields. Reading 0x11410f48 apart:
| Field | Mask | Value | Means |
|---|---|---|---|
| Group | 0xf0000000 | 0x10000000 | SYSTEM |
| Area | 0x0f000000 | 0x01000000 | GLOBAL |
| Type | 0x00ff0000 | 0x00410000 | INT32_VEC |
| Ordinal | 0x0000ffff | 0x00000f48 | 0xf48 |
Reading it from an app
This property is defined in the HAL but is not exposed as a constant in android.car.VehiclePropertyIds, so it is not reachable through CarPropertyManager from an ordinary app. It is used by the platform, or by vendor code running with system privileges.