Complete start-up process under Linu

1:BIOS: boot automatically detects the BIOS (software embedded in hardware) and identifies the first bootable device according to the user's settings

2:MBR: read MBR (main bootstrapper partition block) in first sector of first bootable device, boot loader (boot loader) in MBR

3:boot loader: load kernel file, start operating system

Additional Features:

1: Provides menu options, user can choose other boot options, multi-boot

2: Transfer the boot load function to other loader (boot loader can be installed in the MBR as well as in the boot sector boot sector of other partitions)

4: After the kernel is acquired, it is loaded into memory and hardware detects and loads the driver

5:init process : Kernel actively invokes Init process to get run-level information

run-level:

0-halt: Direct shutdown

1-single User mode: Single-user modes for maintenance in the case of system problems

2-multi-user, without NFS: command-line mode with no NFS service

3-full Multi-User mode: command line with network function

4-unused: System Hold function

5-X11: Graphical interface

6-reboot (restart)

6:/etc/rc.d/rc.sysinit: Init process runs this file to configure the system's basic operating environment (e.g. network environment, storage environment, etc.)

You can use DMESG to see what the system does.

7:/etc/rc.d/rc[0-6].d/*: Init process opens the service under the corresponding Run-level

8:/etc/rc.d/rc.local: Init process runs user-defined script in/etc/rc.d/rc.local

If we want to let the system automatically execute some scripts at boot time, instead of waiting for our login system to start manually, we can write the script to /etc/rc.d/rc.local, then the work will be loaded automatically when it is started.

9: Enter terminal

This article is from the "Call Me boxin" blog, so be sure to keep this source http://boxinknown.blog.51cto.com/10435935/1663832

Complete start-up process under Linu