1 Introduction
In the 11.0 system rom customization development, when developing the hal module, when it is necessary to add a custom hal module to realize some functions, it is necessary to add the relevant functions of the hal module, and then implement a case to for reference
2. The hal layer adds the core class of custom hal module function implementation
hardware\interfaces\3. The core function analysis and implementation of adding custom hal module functions to the hal layer
The full name of HIDL is HAL interface definition language (hardware abstraction layer interface definition language). Before that, Android had AIDL, which was
built on top of Android binder and used to define the interface between Android-based Binder-based Client and Service.
HIDL also has a similar role, except that it defines the interface between the Android Framework and the Android HAL implementation.
HIDL can be divided into: HIDL C++ (C++ implementation), HIDL Java (Java implementation), and is mainly divided into straight-through and binding. The
C++ and straight-through HIDL used in this article realize the above functions.
HAL is The hardware abstraction layer, which shields the hardware implementation details downwards, provides an abstract interface upwards.
HAL is the direct interface between the underlying hardware and the upper framework. The framework layer can operate hardware devices
HAL and kernel drivers through HAL. HAL is implemented in user space. The driver is in the kernel space, so in order to protect the interests of major manufacturers
, the core algorithm and the like need to be implemented in the hal layer
The hardware abstract layer (Hardware Abstract Layer, HAL) of the Android system runs in the user space, which shields the implementation details of the hardware driver module&#x