install grub from ubuntu code example
Example 1: install grub manually
# grub-install --target=x86_64-efi --efi-directory=esp --bootloader-id=GRUBExample 2: install grub manually
# grub-mkconfig -o /boot/grub/grub.cfg# grub-install --target=x86_64-efi --efi-directory=esp --bootloader-id=GRUB# grub-mkconfig -o /boot/grub/grub.cfg