A few files need to be modified to add dynamic sensor support to a device. The dynamic sensor HAL must be enabled in the device product makefile and in the sensor sub-HAL configuration file, support for raw HID devices must be configured in the Linux kernel (CONFIG_HIDRAW=y), and SELinux policy files must be updated to provide the necessary permissions. Example changes are provided below.
Note: as of Android 15, the hidraw_device SELinux label is provided by the system.
acme-co$ git -C device/acme/rocket-phone diff diff --git a/sensor_hal/hals.conf b/sensor_hal/hals.conf index a1f4b8b..d112546 100644 --- a/sensor_hal/hals.conf +++ b/sensor_hal/hals.conf @@ -1 +1,2 @@ +sensors.dynamic_sensor_hal.so sensors.rocket-phone.so diff --git a/rocket-phone.mk b/rocket-phone.mk index 3fc8538..b1bd8a1 100644 --- a/rocket-phone.mk +++ b/rocket-phone.mk @@ -73,6 +73,9 @@ PRODUCT_PACKAGES += sensors.rocket-phone PRODUCT_PACKAGES += thruster_stats +# Add the dynamic sensor HAL. +PRODUCT_PACKAGES += sensors.dynamic_sensor_hal + # Only install test tools in debug build or eng build. ifneq ($(filter userdebug eng,$(TARGET_BUILD_VARIANT)),) PRODUCT_PACKAGES += thruster_test diff --git a/conf/ueventd.rc b/conf/ueventd.rc index 88ee00b..2f03009 100644 --- a/conf/ueventd.rc +++ b/conf/ueventd.rc @@ -209,3 +209,7 @@ # Thrusters /dev/thruster* 0600 system system + +# Raw HID devices +/dev/hidraw* 0660 system system + diff --git a/sepolicy/sensor_hal.te b/sepolicy/sensor_hal.te index 0797253..22a4208 100644 --- a/sepolicy/sensor_hal.te +++ b/sepolicy/sensor_hal.te @@ -52,6 +52,9 @@ # Allow sensor HAL to read thruster state. allow hal_sensors_default thruster_state:file r_file_perms; +# Allow access for dynamic sensor properties. +get_prop(hal_sensors_default, vendor_dynamic_sensor_prop) + +# Allow access to raw HID devices for dynamic sensors. +allow hal_sensors_default device:dir r_dir_perms; +allow hal_sensors_default hidraw_device:chr_file rw_file_perms; + # # Thruster sensor enforcements. # diff --git a/sepolicy/property.te b/sepolicy/property.te index 4b671a4..bb0894f 100644 --- a/sepolicy/property.te +++ b/sepolicy/property.te @@ -49,3 +49,7 @@ # Thruster vendor_internal_prop(vendor_thruster_debug_prop) + +# Dynamic sensor +vendor_internal_prop(vendor_dynamic_sensor_prop) + diff --git a/sepolicy/file_contexts b/sepolicy/file_contexts index bc03a78..ff401dc 100644 --- a/sepolicy/file_contexts +++ b/sepolicy/file_contexts @@ -441,3 +441,7 @@ /dev/thruster-fuel u:object_r:thruster_device:s0 /dev/thruster-output u:object_r:thruster_device:s0 /dev/thruster-telemetry u:object_r:thruster_device:s0 + +# Raw HID device +/dev/hidraw[0-9]* u:object_r:hidraw_device:s0 + diff --git a/sepolicy/property_contexts b/sepolicy/property_contexts index 5d2f018..18a6059 100644 --- a/sepolicy/property_contexts +++ b/sepolicy/property_contexts @@ -104,3 +104,7 @@ # Thruster vendor.thruster.debug u:object_r:vendor_thruster_debug_prop:s0 + +# Dynamic sensor +vendor.dynamic_sensor. u:object_r:vendor_dynamic_sensor_prop:s0 + acme-co$
Once the file modifications are made, rebuild and flash. The dynamic sensor HAL should be initialized and appear in the sensor service.
acme-co$ build_and_flash_android ... acme-co$ adb logcat -d | grep DynamicSensorHal 12-15 18:18:45.735 791 791 D DynamicSensorHal: DynamicSensorsSubHal::getSensorsList_2_1 invoked. 12-15 18:18:47.474 791 791 D DynamicSensorHal: DynamicSensorsSubHal::initialize invoked. acme-co$ adb shell dumpsys sensorservice | grep Dynamic 0000000000) Dynamic Sensor Manager | Google | ver: 1 | type: android.sensor.dynamic_sensor_meta(32) | perm: n/a | flags: 0x00000007 Dynamic Sensor Manager (handle=0x00000000, connections=1) Dynamic Sensor Manager 0x00000000 | status: active | pending flush events 0
When a dynamic sensor is paired with the device (e.g., Bluetooth rocket buds), it will appear in the sensor service.
acme-co$ adb logcat -d | grep "DynamicSensorHal\|hidraw\|Rocket" 12-15 18:19:55.268 157 157 I hid-generic 0003: 1234:5678.0001: hidraw0: BLUETOOTH HID v0.00 Device [RocketBuds] on 12-15 18:19:55.235 791 809 E DynamicSensorHal: return 1 sensors 12-15 18:19:56.239 1629 1787 I SensorService: Dynamic sensor handle 0x1 connected, type 37, name RocketBuds acme-co$ adb shell dumpsys sensorservice | grep head_tracker 0x00000001) RocketBuds | BLUETOOTH 1234:5678 | ver: 1 | type: android.sensor.head_tracker(37) | perm: n/a | flags: 0x00000020 acme-co$