Deprecate [email protected]

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

When Android removes the legacy code path (healthd, [email protected]), [email protected] HAL is deprecated according to deprecation schedule. In addition, Android also removes the following:

1. healthd dependency in framework
2. healthd
3. [email protected] HAL definition library from system
4. [email protected] entry in framework compatibility matrix

Remove 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: "[email protected]_name"
       overrides: ["healthd"],
       // ...
   }
   

   Or, if the module is in Make:

   LOCAL_MODULE_NAME := \
       [email protected]_name
   LOCAL_OVERRIDES_MODULES := healthd
   

   If the default implementation [email protected] is installed, implement a device-specific [email protected]_name instead. For more information, see Implementing Health.