RPTST/dual_boot.txt

## dual_boot.txt
PSA: How to dual boot Pop_OS with Windows with a menu to select from, when you install Pop after Windows in the same drive.
An updated and more complete guide is now found here

Disclaimer: You do this at your own risk.

What you want to achieve:

Install Pop!_OS after Windows on the same drive. You want a menu to pop up after POST so that you can select Pop or Windows.

What is happening:

Pop!_OS uses systemd-boot to start up. This is not grub. It is simple once you get the concept.

How to make the menu appear:

First lets make the menu appear. Normally you need to press the spacebar after POST to make the menu appear. If you want the menu to appear every time, you need to add a timeout to the config file that controls the menu.

This is done by modifying /boot/efi/loader/loader.conf file to add a timeout, so the file looks like this:

default Pop_OS-current
timeout 5
This menu will appear for 5 seconds (hint 5 in the line above). If you want to change the default, you know what to do.

If you reboot now, the menu will pop up, but the options you will see are only

Pop_OS-current kernel

Pop_OS-previous kernel

UEFI menu

The last option just takes you to your systems UEFI (legacy BIOS not supported)

The two Pop entries are for redundancy. If a new kernel update breaks your system, you can always boot the old one and remove it.

How to make Windows appear as an option:

For Windows to appear as an option, systemd-boot requires its EFI files to be in the same partition as those of Pop. You cannot use Windows's EFI partition because it is too small, otherwise, during installation, you could just use that partition for Pop too.

So you will need to copy Windows EFI files onto Pop's EFI partition (that's why when installing its a good idea to make this large, 1GB to be safe).

Find Windows EFI partition and mount it under Pop! so you can copy the files. The Windows partition contains an EFI folder with two subfolders: "Boot" and "Microsoft".

Copy the Microsoft folder to /boot/efi/EFI

This folder also contains a "Pop_OS-fe5b298c-b5ab-4b9d-8476-b5ff61d93baf" folder, along with Recovery, Linux, BOOT, and systemd. The long string after the Pop_OS will be different in your system.

That's it.

Now the menu will appear as follows:

Pop_OS-current kernel

Pop_OS-previous kernel

Windows

UEFI menu

What to set UEFI boot options to:

Set your UEFI to boot from Pop. This will offer you the menu you just made at every boot, and you can boot Windows from it.

How to make Windows the default boot option:

The quickest and easiest way is to hold space when you start to make the menu appear, select with your keyboard arrows the Window option and press d. This will show a => symbol in front of it. This means it is set as default boot option. You can change back to Pop by repeating this and selecting Pop.

You can also go the long way following this:

You will need to create a little loader configuration file. These live inside /boot/efi/loader/entries.

Create a file named Windows.conf

with content:

title Windows Boot Manager
efi \EFI\Microsoft\Boot\bootmgfw.efi
The title can be anything, it appears on the menu at boot. The second line indeed has backwards slashes, just check that the file bootmgfw.efi is indeed in /boot/efi/EFI/Microsoft/Boot/

You can chose Linux on boot from the menu, or by holding **L** after POST.

How to select default boot without editing text files

When you reach the start up menu (hold spacebar after POST), you can select with the arrow keys the option you want to boot by default and press D. You will see => appear next to this and the warning it is the new default.

-------------------------------------------------------------------

DISCLAIMER: You do this at your own risk.


Edit: Tips.

You can reboot from Pop to UEFI (firmware) settings by issuing:

systemctl reboot --firmware-setup
or (if you dual boot with Windows), you can reboot to Windows (straight after reboot, no other input required) by issuing:

systemctl reboot --boot-loader-entry=auto-windows
If you have multiple kernels you can also change the part after --boot-loader-entry= to do that.

Finally, if you want to boot to Windows after POST, you can just hold "w" rather than bring up the menu with space and select. For linux you just hold "l" (letter L).


I hope this helps.
	PSA: How to dual boot Pop_OS with Windows with a menu to select from, when you install Pop after Windows in the same drive.
	An updated and more complete guide is now found here

	Disclaimer: You do this at your own risk.

	What you want to achieve:

	Install Pop!_OS after Windows on the same drive. You want a menu to pop up after POST so that you can select Pop or Windows.

	What is happening:

	Pop!_OS uses systemd-boot to start up. This is not grub. It is simple once you get the concept.

	How to make the menu appear:

	First lets make the menu appear. Normally you need to press the spacebar after POST to make the menu appear. If you want the menu to appear every time, you need to add a timeout to the config file that controls the menu.

	This is done by modifying /boot/efi/loader/loader.conf file to add a timeout, so the file looks like this:

	default Pop_OS-current
	timeout 5
	This menu will appear for 5 seconds (hint 5 in the line above). If you want to change the default, you know what to do.

	If you reboot now, the menu will pop up, but the options you will see are only

	Pop_OS-current kernel

	Pop_OS-previous kernel

	UEFI menu

	The last option just takes you to your systems UEFI (legacy BIOS not supported)

	The two Pop entries are for redundancy. If a new kernel update breaks your system, you can always boot the old one and remove it.

	How to make Windows appear as an option:

	For Windows to appear as an option, systemd-boot requires its EFI files to be in the same partition as those of Pop. You cannot use Windows's EFI partition because it is too small, otherwise, during installation, you could just use that partition for Pop too.

	So you will need to copy Windows EFI files onto Pop's EFI partition (that's why when installing its a good idea to make this large, 1GB to be safe).

	Find Windows EFI partition and mount it under Pop! so you can copy the files. The Windows partition contains an EFI folder with two subfolders: "Boot" and "Microsoft".

	Copy the Microsoft folder to /boot/efi/EFI

	This folder also contains a "Pop_OS-fe5b298c-b5ab-4b9d-8476-b5ff61d93baf" folder, along with Recovery, Linux, BOOT, and systemd. The long string after the Pop_OS will be different in your system.

	That's it.

	Now the menu will appear as follows:

	Pop_OS-current kernel

	Pop_OS-previous kernel

	Windows

	UEFI menu

	What to set UEFI boot options to:

	Set your UEFI to boot from Pop. This will offer you the menu you just made at every boot, and you can boot Windows from it.

	How to make Windows the default boot option:

	The quickest and easiest way is to hold space when you start to make the menu appear, select with your keyboard arrows the Window option and press d. This will show a => symbol in front of it. This means it is set as default boot option. You can change back to Pop by repeating this and selecting Pop.

	You can also go the long way following this:

	You will need to create a little loader configuration file. These live inside /boot/efi/loader/entries.

	Create a file named Windows.conf

	with content:

	title Windows Boot Manager
	efi \EFI\Microsoft\Boot\bootmgfw.efi
	The title can be anything, it appears on the menu at boot. The second line indeed has backwards slashes, just check that the file bootmgfw.efi is indeed in /boot/efi/EFI/Microsoft/Boot/

	You can chose Linux on boot from the menu, or by holding L after POST.

	How to select default boot without editing text files

	When you reach the start up menu (hold spacebar after POST), you can select with the arrow keys the option you want to boot by default and press D. You will see => appear next to this and the warning it is the new default.

	-------------------------------------------------------------------

	DISCLAIMER: You do this at your own risk.



	Edit: Tips.

	You can reboot from Pop to UEFI (firmware) settings by issuing:

	systemctl reboot --firmware-setup
	or (if you dual boot with Windows), you can reboot to Windows (straight after reboot, no other input required) by issuing:

	systemctl reboot --boot-loader-entry=auto-windows
	If you have multiple kernels you can also change the part after --boot-loader-entry= to do that.

	Finally, if you want to boot to Windows after POST, you can just hold "w" rather than bring up the menu with space and select. For linux you just hold "l" (letter L).



	I hope this helps.