Android's system architecture

Android's system architecture incorporates the idea of a layered architecture, as shown in 1. The top-to-bottom layer consists of four tiers, namely the application program layer, the application framework layer, the system library and the Android runtime and the Linux kernel.

Figure 1:android System architecture diagram

Each layer features a brief introduction as follows:

an application layer

The tier provides core application packages such as e-mail, text messages, calendars, maps, browser and contact management. At the same time, developers can use the Java language to design and write their own applications, which are equal and friendly with those core applications.

Two application framework layer

This layer is the basis for Android app development, and most of the time developers are dealing with her. The application framework layer includes the Activity Manager, window Manager, content provider, view system, Package Manager, Phone manager, resource manager, Location manager, Notification Manager, and XMPP Services 10 sections. On the Android platform, developers have full access to the API framework used by the core application. Also, any application can publish its own module of functionality, while other applications can use these published function modules. Based on this reuse mechanism, users can easily replace the various application components of the platform itself.

three system libraries and Android runtime

The system library consists of nine subsystems, layer management, Media Library, SQLite, Openglestate, FreeType, WebKit, SGL, SSL, and libc. The Android runtime includes both the core library and the Dalvik virtual machine, which are compatible with the function functions that most Java languages need to invoke, and the core libraries of Android, such as Android.os, Android.net, Android.media, and so on. The latter is a register-based Java Virtual machine,Dalvik virtual machine is to complete the life cycle management, stack management, thread management, security and exception management, garbage collection and other important functions.

Quad Linux kernel

Android Core system services rely on Linux2.6 cores such as security, memory management, process management, network protocol stacks, and drive models. The Linux kernel is also an abstraction layer for hardware and software stacks. Drivers: Display drivers, camera drivers, keyboard drivers,WiFi drivers,audio drivers,flash memory drivers,Binder (IPC) drivers, power management, and more.

Summarize:

The 1 Android system architecture uses a layered architecture concept that is structured and structured to work together.

The 2 Android system Architecture not only recognizes the Android system from the macro level, but also gives us a direction for our learning and practice. If you're working on Android apps, you should study Android's application framework and application layer, and if you're working on Android, you should study Android's system library and Android runtime, and if you're working on Android-driven development, That should study Android's Linux kernel. In short, find the right entry point, practice the truth.

Android's system architecture