Hi Petr! > Do you know how to fix this issue? Yes. Like on other EFI systems, you have to mount /dev/mmdblk0p1 on /mnt/boot/efi. There is the usual bootloader installation fallback, to use the bootloader-target argument for installation on /, if it is not existing below /mnt. And this is happening in your case. I don’t understand why this common fallback got invented. I think it’s actually dangerous. It could destroy your booted system, if you simply forgot to mount the EFI system partition. I would prefer a clear error message. But well, the code is following existing standards. > 1) Why does it point to "/boot/efi/gnu/store" and not "/mnt"/boot/efi/gnu/store"? Because /mnt/boot/efi was not existing in your case and because of that fallback to ignore /mnt and use / instead. > 2) Symlink from ext4 "Guix" partition will not work on another vfat "EFI" partition. That’s true. This symlink will not be created for your use case. The symlink will be created for booting over network, when the /mnt/boot/efi is an NFS share which allows symlinks. The use-case decision is based on symlink support at the bootloader-target. Actually the installation on a microSD card is just a by-product of installation for netboot. :-) Even on a normal x86_64 EFI system you could install the grub-efi-netboot-(removable-)bootloader instead of the grub-efi-(removable-)bootloader. The difference is, that all GRUB files will reside on the EFI system partition instead of the root partition. This could be helpful for encryption problems. Bye Stefan