Deprecating health@1.0

The framework will continue to work with health@1.0 until it is fully deprecated according to the standard HAL deprecation schedule. When health@1.0 is deprecated (entry removed from framework compatibility matrix), healthd and libbatterymonitor must also be removed from system to avoid unknown behaviors for healthd. As health@1.0 is an optional HAL and all healthd dependencies to health@1.0 are guarded by NULL checks, nothing should break on deprecation.

When Android removes the legacy code path (healthd, health@1.0), Health@1.0 HAL is deprecated according to deprecation schedule. In addition, Android also removes the following:

1. healthd dependency in framework
2. healthd
3. health@1.0 HAL definition library from system
4. health@1.0 entry in framework compatibility matrix

Removing healthd

For devices launching with Android 9 and devices upgrading to Android 9 that provide the Health 2.0 HAL in the new vendor image, we recommend removing healthd from the system image to save disk space and speed boot time.

To do so:

1. Remove healthd and healthd.rc from the system image by adding the following line to the device-specific implementation in Soong:

   cc_binary {
       name: "android.hardware.health@2.0-service.device_name"
       overrides: ["healthd"],
       // ...
   }
   

   Or, if the module is in Make:

   LOCAL_MODULE_NAME := \
       android.hardware.health@2.0-service.device_name
   LOCAL_OVERRIDES_MODULES := healthd
   

   If the default implementation android.hardware.health@2.0-service is installed, implement a device-specific android.hardware.health@2.0-service.device_name instead. For more information, see Implementing Health.