The first OS on laptop was Windows 10. After that, I have added Manjaro. Manjaro has added a Grub menu, with entry's for Manjaro and Windows. Now I want to switch to Arch. I have installed Arch on a separate partition. Arch has not added a entry in this grub menu, but this was expected. I have used update-grub from Manjaro, what added Arch to the menu.
But for some reason I can't edit the menu from within Arch.
I have tried to understand Arch Wiki what I have to do, to edit this menu from Arch. Can someone please help me to get this to work? I have tried to add my EFI partition /dev/sda1 via fstab to /boot/efi like in Manjaro, but this doesn't help to find the same menu with grub-customizer.
I'm a gentoo user, so I don't know how either manjaro or arch lay out their partitions. But in my case, the grub.cfg (menu) file is actually on the root partition, in /boot. The efi partition contains only the grub loader, which I presume knows where to look for grub.cfg because that's how grub2-setup installed it.
It's possible you have a similar issue. Your manjaro partition may have a /boot dir which is where grub.cfg is located. Even if your arch partition also has /boot it won't matter if the grub loader doesn't read it.
I have used the command grub-install --target=x86_64-efi --efi-directory=esp --bootloader-id="Arch Linux" before, but without success. This didn't worked before. But now...