Linux kernel (i) system boot process

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(1) Initialization of the CPU itself:

A series of initialization work is required after CPU power is added.

(2) CPU load BIOS ( basic inputoutput System " :

CPU performs a fixed position Span style= "Font-family:"times new roman"" > ( 0xfffffff0" bios code header. bios Curing on the motherboard a very small rom

(a) power-on self-test (POST) : Complete System hardware ( memory, system bus, etc. " detection;

(b) Load kernel boot program: reads the master boot record MBR ( The first sector of the boot device ), andtheMBR saves at the beginning of thekernel boot program, theBIOS loads the MBR and executes it.

(3) boot loader load kernel image :

The kernel boot program is divided into two phases:

(a) The master boot program scans the partition table and loads the secondary boot program in the active partition boot record into memory and executes;

(b) The secondary boot loader is responsible for loading the kernel image into memory;

(4) The kernel image starts to work:

self-extracting, and then calling init/main.c in the Start_kernel () function execution;

At this point the kernel boot process has ended, the following into the kernel initialization process!!!

the initialization of the kernel takes Start_kernel () function starts until the first user process Init End:

(1) Start_kernel () function: the man function that corresponds to the entire initialization of the kernel .

Completion of most of the kernel initialization work, mainly storage management, device management, file management, process management, such as the initialization of tasks;

(2) Reset_init () function: Subsequent initialization, called by the Start_kernel () function;

(3) Kernel_init () function: completes initialization of the device driver and invokes the init_post () function to start the init in user space process;

(4) Init_psot () function: starts the init process in user space ,theinit standard location in /sbin/init, theinit process reads the /etc/inittab file to trigger such as accepting user login, Set up the keyboard, network, and other processes. This system has been successfully started!!!

Linux kernel (i) system boot process