One-to-N Implementation GRUB guides multiple operating systems

Article Title: One-to-N Implementation of GRUB guides multiple operating systems. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
In the installation of multiple operating systems, GRUB is sometimes lost. For example, when I reinstall XP, XP clears GRUB from MBR. In addition, GRUB installation fails or enters the console status during LINUX upgrade, and GRUB needs to be re-installed.
　　
GRUB has many functions. For general users, You Need To Know ROOT, SETUP, INSTALL, ROOTNOVERIFY, CHAINLOADER, and GRUB. CONF for STAGE1 and STAGE2 files in different file systems.
You don't need to download GRUB or anything. Generally, you don't need to download GRUB.
　　
The ROOT format is ROOT (HDX, Y)
X is from 0---N, and Y is also. The first hard disk, the first partition is (HD0, 0), the first hard disk, and the second partition is (HD0, 1 );
The second hard disk, the first partition is (HD1, 0), the second hard disk, and the second partition is (HD1, 1). Similarly, you can know the ROOT usage.
ROOT is the command for GRUB to identify the hard disk and file format, telling GRUB what the Startup Device is and how to MOUNT the file format of the Startup Device. In the next step, you can find the GRUB configuration file and start the core, or start the imgfile.
　　
SETUP and install grub to a specified location, such as MBR. For details, see the HELP file.
　　
For different file systems, STAGE1 and STAGE2 can be found in the GRUB package or in the/USR/SHARE/GRUB directory, and copied to the GRUB directory.
　　
The format of GRUB. CONF is as follows:
Default = 0
Timeout = 10
Splashimage = (hd1, 2)/boot/grub/splash.xpm.gz
Title WindowsXP
Rootnoverify (hd0, 0)
Chainloader + 1
Title RedHat9
Root (hd0, 1)
Kernel/boot/vmlinuz-2.4.20-8 ro root = LABEL =/
Initrd/boot/initrd-2.4.20-8.img
Title Mandrake9.1
Kernel (hd1, 4)/boot/vmlinuz root =/dev/hdb5 quiet devfs = mount acpi = off vga = 788
Initrd (hd1, 4)/boot/initrd. img
　　
Default = X is the default system, 0 is the first system, and so on.
Timeout = X indicates the residence time of the Grub menu, in seconds.
Title XXX, XXX is the title, that is, the name of the operating system you want to boot, you can modify it by yourself
　　
Rootnoverify (hd0, 0) tells gnu grub where your Widnows C disk is, but do not try to mount it ('noverify ', optional ). Chainloader + 1 tells gnu grub not to load Windows by itself (which cannot be completed by itself), but to hand over the startup process to the first sector of drive C, which contains the original DOS/Windows Startup Program.