2 - Linux and Android Boot Processes

Question 1

Linux Boot Process

Answer 1

BIOS
GRUB 1
GRUB 2
Kernel

Question 2

BIOS (Linux Boot Process)

Answer 2

POST

Initial hardware setup and config

Select boot device and execute boot loader

Question 3

GRUB 1

Answer 3

Small machine code on MBR

Find and load GRUB 2

Question 4

GRUB 2

Answer 4

Select Kernel

Load initrd into memory

Load drivers required to complete boot

Load kernel into memory

Question 5

Kernel (Linux Boot Process)

Answer 5

Initialize and configure memory and hardware

Mount initrd and load necessary drivers and kernel modules

Mount root filesystem

Execute /sbin/init

Question 6

Android Boot Process

Answer 6

Boot ROM
Boot Loader 1
Boot Loader 2
Kernel
Init
Zygote
System Servers
Home App
Contacts (if opened)

Question 7

Boot ROM (Android Boot)

Answer 7

Perform check of all chip components

Detect boot media

Locate and execute Boot Loader

Question 8

Boot Loader 1 (Android boot)

Answer 8

Detect and set up external RAM

Load Boot Loader 2

Question 9

Boot Loader 2

Answer 9

Set up hardware such as networking/additional memory

Find and load linux kernel

Question 10

Kernel (Android Boot)

Answer 10

Setup memory protections, caches, and scheduling

Start init process

Question 11

Init (Android Boot)

Answer 11

Start each system service daemon

Start Zygote Process

Start Runtime Process (which start service manager)

Question 12

Zygote

Answer 12

Runtime process tells Zygote to start system server

Listen for requests for, and launch, Dalvik VM instances

Question 13

System Servers

Answer 13

Start native system servers

Start Android Managed services (those in the application framework layer)

Question 14

Home App

Answer 14

Idle screen

Loaded by Zygote in new Dalvik VM

Boot process complete