Linux boot process, linux Process

Linux boot process, linux Process

 

1. Load BIOS

When you turn on the computer power, the computer will first load the BIOS information, BIOS information is so important that the computer must find it at the very beginning. This is because the BIOS contains CPU information, device startup sequence information, hard disk information, memory information, clock information, pnp, and so on. After that, the computer information will be analyzed and you will know which hardware device you want to find.

2. Read MBR

In all, the first sector of the 0th track on the hard disk is called MBR, which is the Master Boot Record. The size of this record is 512 bytes, which stores the startup information and partition table information.

3. Boot Loader

It is a short program that runs before the operating system kernel runs. Through this applet, We can initialize hardware devices and create a map of memory space to bring the system's hardware and software environment to a suitable state, in order to make all preparations for the final call to the operating system kernel.

4. Load the kernel

5. User-layer init sets the running level based on the inittab File

6. Execute rc. sysinit in the init program.

7. Start the kernel module

8. execute script programs of different running levels

9. Run/etc/rc. d/rc. local.

10. Run the/bin/login program