Linux startup process GRUB detailed

What is the boot process for Linux? How to complete the system startup through grub boot? These problems have not been thoroughly studied before I installed the dual system. Understand Linux booting through grub, can help us understand the Linux operating system
, and also popularize the basic knowledge ^_^.

As shown in the figure, this is a schematic diagram of the Linux partition of a hard disk. Useful for 4 primary partitions, including boot, root, swap, and home; the linux boot file is placed in the first space of the hard drive. The linux boot file is similar to the windows system. The only difference is the grub data structure.

Similar to windows, the first 512 bytes of the first sector of the hard disk store the master boot record (MBR); the MBR includes a 444-byte Boot Loader, a 64-byte partition table and 2 bytes of flag (0xAA55). This 512-byte message is very important. If it is damaged, it will cause failure to boot the Linux system; so we should make a backup at the appropriate time:

# /dev/hda This is your hard drive. The first partition can be changed according to the actual situation dd bs=512 count=1 if=/dev/hda