Android Overall Architecture Overview--①

The Android logo is inspired by the designer's visit to the toilet.

The name of Android is named after the dessert.

Android's system has a total of four layers.

1.Linux Core and drive layer

2. Function libraries are written in C or C + +

3.Application Framework Application Frame layer

4. Application Layer

The introduction of the JVM and the DVM translates Java into a machine-readable language.

The JVM was developed for sun company. Stack-based architecture. Java->class->.jar

The DVM (Dalvik vm) is Google's own design of the virtual machine DVM (for copyright reasons).  A register-based architecture. Java->class->.dex->.odex

After the Android 4.4 version, join the art mode. The APK package can be compiled when the program is installed. Eliminates the need for a DVM to convert code in real time.

However, the memory consumption of the program is larger.

Android Overall Architecture Overview--①