Android framework architecture HAL folder

Question

What is difference in folders hardware/ device/ vendor/ framework/ from AOSP I cannot understand what the rules/relation from the folders

Regards Peter

Answer 1

• hardware/
  Before "Project Treble", vendors would put their implementations of the hardware layer in this directory. However, these should now be located in vendor/<vendor>/interfaces/.

  • hardware/interfaces/
    Contains the hardware abstraction layer interface definition (HIDL), as well as some dummy implementations for the same.
  • hardware/libhardware/
    Contains the legacy hardware abstraction layer interface definition.

• device/
  Contains device configurations. A device is a mobile phone, a tablet, a VR headset, and so on. If you build Android you always have to specify which device you want to build.

• vendor/
  Contains software that is provided by a vendor and not by the AOSP. You will find the implementation of the hardware layer, vendor-specific services as well as framework extensions in this directory.

• framework/
  Contains the Android application framework.