Arch Linux

Mowgli

Member

Registered: 2021-11-11

Posts: 15

GRUB not showing at startup

Hi!
So here is my concern: I've installed arch linux alongside windows10 a couple of days ago but I'm having problem to dual boot. To be more precise I can only boot into arch from the bios(not really the bios but by pressing f9 to enter the boot option menu) since it logs me directly into windows10. But I've somehow managed to bring up the grub when booting by copying the ~/grubx64.efi to the /boot/EFI/Microsoft/boot/bootmgrfw.efi directory. But the problem now is I can boot normally into arch but I can´t boot into windows10 since whenever I click on Windows10 on  the grub menu, it turns me back to the grub menu instead of starting Windows. So windows become unreachable.

Note that I still can start windows but by modifying the /boot/EFI/Microsoft/boot/bootmgrfw.efi  to it's original state but no more grub.

Thanks.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,299

Re: GRUB not showing at startup

Which of course makes sense. However the entire point of UEFI is that you can have multiple loaders without such shenanigans.

What's your mainboard? Sometimes you need to add explicit entries via their own firmware because they don't allow outside manipulation. If it's MSI copy the grub.efi to the actual fallback location or do the reverse of what we usually do and add GRUB to Windows' UEFI loader: https://wiki.archlinux.org/title/Unifie … mware_menu

If you don't want to do these and want to check what's actually detected post

sudo efibootmgr -uv

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 9,003

Website

Re: GRUB not showing at startup

You could copy the Windows bootmgfw.efi to somewhere else and chainload it from GRUB.

For example (replace $uuid with the actual UUID of the partition containing bootmgfw.efi):

menuentry 'Windows' {
   search --fs-uuid --set=root $uuid
   chainloader /path/to/bootmgfw.efi
}

Note that Windows will probably try to "fix" your hack when it updates. You could create a batch file in Windows to revert this and make it run at every boot. Use the mountvol command to mount the ESP in Windows.

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Jin, Jîyan, Azadî