|Android| How was the Android system after power up?

This article will stand on high level to scan initialization modules.

User press power key ……

First, Boot ROM
 - Loads the BootLoader into RAM and starts executing.

Second, BootLoader
 - Start up and find the system kernel.
 - Bootloader is a place where manufacturers put their locks
  and restrictions.
 - Detects external RAM
 - Setups the network, memory … etc, which requires to run Kernel.

Third, Kernel
 - Setup cache
  Protected memory
  Scheduling
  Loads drivers
  Starts kernel daemons
  Mounts root file system
  Initializing Input/Output
  Starts interrupts
  Initializes process table ……
 - Looks for “init” in system files
 - Launch root process

Forth, Init (user space)
 - Mounts directories like /sys, /dev or/proc
 - Runs /init.rc script. The init.rc is responsible for the initial set up of the system.

Fifth, (Android) Zygote: 
 - VM process that starts as the system boots
 - app_process launces Zygote

Sixth, SystemServer
 - Load a native library called android_servers

ref. for Android: https://maoao530.github.io/2017/01/06/android-start/

refs.
https://blog.csdn.net/a4262562/article/details/76779236
https://danielmaker.github.io/blog/linux/start_kernel.html
https://cjworld1208.pixnet.net/blog/post/8014497
http://embeddedvenkatpari.blogspot.com/2016/05/how-to-load-firmware-using-pil.html?m=1
https://www.twblogs.net/a/5b8d19262b717718833b2c22
http://albert-oma.blogspot.com/2016/07/embedded-u-boot.html?m=1