Android system porting and driver development

Chapter One: Android system porting and driver development

This chapter is the first door to learn Linux drivers, mainly for Android and Linux driver to do a general introduction, learning Android Driver Development, is actually learning Linux driver development, but Android added a HAL, which is unique to Android.

First of all to understand the composition of the Android system architecture, followed by the Android system porting the main work, and learn to see the Linux kernel version and its Linux kernel version number definition rules, followed by the Linux device driver, finally see what is called Linux driver: LED.

(1) Composition of Android system architecture

Android's system architecture , like its operating system, employs a layered architecture. From the architecture diagram, Android is divided into four tiers, from the high-level to the lower-level, the application layer, the Application framework layer (Android SDK API), the System runtime layer, and the Linux kernel layer. Blue Represents the Java program, yellow code for running Java program implementation of the virtual machine, green part of the C + + language program library, red Code kernel (Linux kernel +drvier)

The layering part needs to be mastered. (See book P4 for details)

(2) The main work of Android system transplant

Android migration can be divided into two parts: application porting and system porting, and application porting refers to porting an application to a specific hardware platform. System porting refers to the Android operating system running on a particular hardware platform. Android's consistent main work consists of two parts: porting the Linux driver and porting the HAL

(3) View definition rules for Linux kernel version and its Linux kernel version number

There are two ways to view the Linux kernel version: Uname–a and Cat/proc/version

Definition rule for Linux kernel version number: Major Version number

Minor version number, which indicates a stable version

Revision number, indicating the number of changes

Fine-tune the version number

(4) Linux device driver: This part is only understood.

Summarize:

Although the Linux kernel version is updated quickly, the Linux driver development methods and procedures are basically the same, as long as a Linux kernel version of the driver development, the other Linux kernel version is basically mastered.

Android system porting and driver development