How to Change Grub Boot Menu order on Linux Mint or Ubuntu
Grub for dual boot operations where multiple Linux distributions or Linux and Windows are installed with the Grub Boot Manager, it may be preferable to change the boot order or the default boot entry occasionally so that the most frequently used operating system is selected first by default.
Assuming it is dual boot with Windows and Linux Mint, this boots first by default, now we would like to start Windows instead without making a selection.
To change Grub Boot Menu order, load the grub file into the editor of your choice.
$ sudo nano /etc/default/grub
Search the content.
GRUB_DEFAULT=0
Then modify the entry, to set Boot Menu order.
GRUB_DEFAULT=2
Note: The index begins at 0, consequently Windows has number 2.
Save the file and exit the editor by pressing Ctrl + O then Ctrl + x to exit nano.
Now update grub menu with this command.
$ update-grub
Finished! Reboot the computer and check the new boot order.
Linux Boot Process
The boot process on Linux is a series of activities that occur from the time you press the power button on your PC until the time the login screen appears.
There are four main stages in the boot process of your operating system and they occur in the following order:
BIOS: Basic Input/Output System
BIOS: Stands for Basic Input/Output System and is mainly responsible for loading the bootloader. When the computer starts, it runs a Power On Self Test (POST) to make sure that core hardware such as the memory and hard disk is working properly. Afterward, the BIOS will check the primary hard drives’ Master Boot Record (MBR), which is a section on your hard drive where the bootloader is located.
Bootloader
Bootloader: Loads the kernel into the RAM with a set of kernel parameters.
Linux Kernel
Kernel: The kernel’s primary function is to initialize devices and memory. Afterward, it loads the init process.
Init process
Init: Responsible for starting and stopping essential services on your system.