Talk:Dual Boot Linux and Linux

Bootloader

As of Mint 19.2 the default bootloader is Grub2 or specifically grub-install (GRUB) 2.02-2ubuntu8.13

You may find that you want to change the order of the operating system options or set a default boot option.

technical point: GRUB 2 works like this: /etc/default/grub contains customization; /etc/grub.d/ scripts contain GRUB menu information and operating system boot scripts. When the update-grub command is run, it reads the contents of the grub file and the grub.d scripts and creates the grub.cfg file.

The problem is that mint is lazy using an os prober script that grub reads each time and it creates the boot order. It is a pain to deal with this because you would have to manually create a script for each os in /etc/grub.d since none exists other than it relying on os-prober. GRUB2 kinda sux.

os-prober

without

root@leia:/etc/grub.d# update-grub
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/50_linuxmint.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-54-generic
Found initrd image: /boot/initrd.img-4.15.0-54-generic
Adding boot menu entry for EFI firmware configuration
done

with

root@leia:/etc/grub.d# update-grub
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/50_linuxmint.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-54-generic
Found initrd image: /boot/initrd.img-4.15.0-54-generic
Found Linux Mint 18.3 Sylvia (18.3) on /dev/sda4
Adding boot menu entry for EFI firmware configuration
done

GRUB2

From the GRUB 2 menu at boot, the user can also determine which Linux is controlling the boot on a multi-OS system. By default, the first menuentry always lists an option from the installation which is in charge of GRUB 2. For example, if the first menuentry contains "on sda5, then the GRUB installed on sda5 OS is controlling the menu/boot.