Are there any blogs that study the source code of android system?

I have been developing the Android sdk for three years, and I feel tired and I can't go on, so it took me more than a year and I probably touched the door. According to the experience of predecessors, it takes two years to fully get into the bottom of Android.

Let me talk about my entry process first:

Step zero, download the source code. I downloaded 4.2, the frame layer source code is 10G, and the kernel is 2G. The tag files built by ctags for the framework layer are all 600M, which shocked me a little at that time. I saw them with vim+ctags+cscope, which is not bad and the architecture is quite clear.

The first step is to find a good book "Design and Implementation of the First Volume of Android", which talks about the startup, initialization, service framework initialization, Binder, message cycle, PackageManagerService and ActivityManagerService of Android framework layer. According to the author, the second volume of UI subsystem will be published later, so we will wait and see. In fact, after reading dozens of pages of this book, I found that I needed the knowledge of the second step, or I couldn't read it any longer and jumped to the second step.

The second step is to learn Linux system programming. When reading Design and Implementation of Android, I found that the native part of the framework layer is Linux programming. In order to master this knowledge, I spent four months studying the Linux System Programming Manual (TLPI), which has more than 1000 pages. I have worked as a WIndows file system before, so the C language is quite familiar. The practice of TLPI is very interesting and the amount is relatively large. I have gained a lot by persevering.

In the third step, I spent four months learning some knowledge about Linux kernel and watching more than half of LKD and PLKA. The more I learn, the less I know. I feel that I don't understand more and more, but this is normal. I have to grind it slowly. It is estimated that this piece will continue to be ground in the future.

The fourth step is to look back at the Android source code. This time, I finished the design and implementation of Android Volume I in one breath, and finally got a framework layer spectrum. I really fainted several times at the same time. I didn't feel so dizzy after reading the source code of the Linux kernel in front. Jumping between the Java layer and the native layer is a bit nerve-racking. Among them, I think the foundation of Java is not too strong, so I went back to make up the eighth edition of the core Java for a month. But this book doesn't involve the UI subsystem, so I read the Android kernel analysis again.

The fifth step is "Android Kernel Analysis" (this book is actually about the framework layer, and the author is also embedded, so the writing of the framework layer is not very good and verbose, but there are still many points to watch. Later, when he wrote ROM and played the development board, it was estimated that he was talking about his own line. After all, he was fine when he strolled. After all, this book is a bit old, and many codes are out of date. However, many of the author's viewpoints are of great reference value. This book is still very weighty about UI subsystem and key/touch message processing system, especially in chapter 13, which draws views and combines source code research with great gains. Later, he said that the compilation framework and ROM-related things are valuable materials.

In the sixth step, in order to make up the knowledge of other subsystems such as power management module, I watched the series "Learn more about android". Personally, I think this series looks a little uncomfortable, but it is still valuable as a supplementary proof.

The seventh step is the scene analysis of the source code of Android system. Luo Shengyang's masterpiece of source code analysis is more detailed than the design and implementation of Android, but the disadvantage is that there are fewer modules involved and the selected source code is slightly older than the design and implementation of Android. After reading the book, you need to study the author's blog. There are many things that will definitely satisfy you.

Step eight, buy a development board and play by yourself. I haven't reached this point yet, because I think I have almost prepared my knowledge. It may take a few months, and then we are going to put 64 10 or raspberry pie.

Finally, because 1 1 did Windows years ago, I don't know much about Linux, so I should read this kind of book. If I have been doing Linux, I think many steps can be omitted. Directly on the source code is the right way.

I am a mobile GIS developer myself, and I am interested in learning the framework layer, but the recruitment platform Android framework layer developers are quite competitive. There are many customized Roms, and the work of smart TV is in a state where talents are hard to find. After all, there is a certain threshold. Now all kinds of ios training make people plunge into development, and the shortcomings that ios can only do sdk development are exposed. I don't think it's good that a bunch of novice cows are crowded into SDK development. On the other hand, on the Android side, although novices don't make money from ios, they are very persistent, and they are made from the sdk- Framework driver kernel. There are also many people who find themselves gradually becoming Linux developers/embedded developers. Newcomers, veterans and novices are all in their respective positions, and the level is very good.

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