First chapter Impressions

Android is a very good embedded operating system, through the first chapter of the reading, I learned a lot about the operating system of the basic knowledge, I think these bases on the subsequent study will be a great help.

I learned that Android architecture is divided into 4 tiers: The first tier: the Linux kernel (drivers and programs that manage resources such as memory, process, power, and so on). The second layer: C + + code base (including the. so file for Linux and the DNK code embedded in the SPK program). Third layer: Contains the Android SDK API directly to the application-oriented Java APK. Layer Fourth: Refers to applications that are directly oriented to end-user Java applications. System architecture requires that these 4-tier applications complement each other and become an operating system requirement.

There are two types of porting and system porting for Android systems. These migrations are largely a migration of the Linux kernel. Linux kernel porting is primarily a porting driver. The Linux kernel version has three main versions, Linux2.4, Linux2.6, and linux3.x. The Linux kernel version number consists of the main version number, the minor version number, the revision number, the fine-tuning version number, and the special tuning description for the specific Linux system. One of the most important is the knowledge of Linux device drivers, including the development of device drivers and the classification and characteristics of equipment. The driver targets the memory and peripherals, not the CPU cores. Linux divides memory and peripherals into 3 categories: Character devices, block devices, and network devices.

From the first chapter to feel, it is necessary to understand that the Linux driver is only related to its kernel, and the user's system does not have any relationship, the Android operating system is a complete operating system, we need to learn and understand, in-depth discussion of the operating system on the Linux learning has a great help.

First chapter Impressions