AFter Windows 10 did an update the otehr day, GRUB no longer appears. At first it was booting straight into Win 10, but after rebooting it just went straight to Asus BIOS.
I have the boot order to start with the Adata M2 where Grub and OS’es are installed, and then second option the same M2 but with “(Windows boot loader)” in next to it. Neither of these work and just loop back to the BIOS.
Putting in my Manjaro install USB gives the live USB menu, which detects the existing EFI and asks if I want to boot fdrom there. And then GRUB comes up as usual with options to start Manjaro. Everything works just fine then.
I just can’t work out how to get the PC to work with GRUB without using a live USB.
So what you’re going to have to do is boot the manjaro liveusb, then mount your root, efi and boot partitions in /mnt.
You’ll also need a few special mounts:
mount --rbind /dev /mnt/dev
mount --rbind /sys /mnt/sys
Once that’s done run chroot /mnt /bin/bash to chroot into your install.
From there, you can run grub-install for your drive. I’m not sure what your drive layout looks like, but since you’re on manjaro, I’m assuming you’re going to be able to sort this out for yourself.
grub-install /dev/sdxy
Then you should run a grub-mkconfig -o with the path to your UEFI grub config (I don’t remember where this is on manjaro, I’d just look around in your boot partition.
Sorry this couldn’t be more in-depth, I’m on mobile.