bug#30312: documentation: misleading EFI partitioning instructions

[Ricardo Wurmus]

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