Android STMicroelectronics SensorHAL Documentation
In order to correctly use Android SensorHAL, modifications at Android code
are necessaries.
Linux device drivers permissions:
First at all, SensorHAL needs to read/write sysfs files and char devices
of IIO drivers.
device/{vendor}/{product}/uevent.{board}.rc file modification is mandatory,
you can find an example in this folder with 'uevent.example.rc'.
Factory calibration option:
If you build the HAL using Factory calibration option, modifications of
SELinux policy are necessary in order to read/write /persist and
/data filesystem.
You can find an example of modifications into the folder factory_calibration.
Those modifications will touch:
- device/{vendor}/{product}/BoardConfig.mk (modification)
- device/{vendor}/{product}/init.{board}.rc (modification)
- device/{vendor}/{product}/sepolicy/file.te (modification)
- device/{vendor}/{product}/sepolicy/file_contexts (modification)
- device/{vendor}/{product}/sepolicy/STSensors.te (add)
Selftest tool manual:
If you build HAL enabling Selftest functions, an executable will be
available and installed into /system/bin/STSensor_selftest.
Using this binary you will be able to easly execute selftest,
based only on Android sensor handle. No information about device
driver will be used.
You can run binary directly in your device using adb shell. All sensors
must be switched off in order to execute the test.
NOTE: Selftest tool is maintained for compatibility with the past Android
version (last successfully tested version was 8.0) but will soon be removed
and no longer supported.
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