The manual section “Preparing for Installation: Disk Partitioning” says this:
--8<---------------cut here---------------start------------->8--- If your disk uses the GUID Partition Table (GPT) format and you plan to install BIOS-based GRUB (which is the default), make sure a BIOS Boot Partition is available (*note (grub)BIOS installation::). If you instead wish to use EFI-based GRUB, a FAT32 “EFI System Partition” (ESP) is required. This partition should be mounted at ‘/boot/efi’ and must have the ‘esp’ flag set. E.g., for ‘parted’: parted /dev/sda set 1 esp on Once you are done partitioning the target hard disk drive, you have to create a file system on the relevant partition(s)(1). For the ESP, if you have one and assuming it is ‘/dev/sda2’, run: mkfs.fat -F32 /dev/sda2 --8<---------------cut here---------------end--------------->8--- First, this sounds like it’s up to the user to pick either EFI-based GRUB or BIOS-based GRUB. It is not clear that this is determined by whether the machine has a {BIOS, EFI in legacy mode} or EFI. It’s really not much of a choice. Second, the “parted” command operates on the first partition (“1”), yet for the second command the second partition (“/dev/sda2”) is used. It’s better to be consistent here, i.e. to change “set 1 esp on” to “set 2 esp on” and to state that this would modify “/dev/sda2”. Finally, it is not clear where the efi partition should be mounted. Should it be /mnt/boot/efi? If so, should the configuration file specify “/mnt/boot/efi” as the target? Or should it be “/boot/efi”? An example would be useful here. -- Ricardo