Re: [PATCH] BIOS boot vs EFI system partition mountpoint

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sat, 20 Aug 2022 12:00:31 +0000
    From:        Taylor R Campbell <riastradh%NetBSD.org@localhost>
    Message-ID:  <20220820120026.B273F609EB%jupiter.mumble.net@localhost>


  | I'd like to have a standard mount point for the EFI system partition
  | on platforms with EFI boot.

I use /efi ... just seemed like the obvious thing to do to me.

  | I propose to change NetBSD/x86 BIOS boot so it looks for the secondary
  | bootloader at /biosboot instead of /boot, but falls back to /boot.

I think that's a very poor idea, sorry.   Not what that paragraph implies,
but ...

  | and we can have /boot as the standard mount point for ESP on
  | platforms with EFI boot.

this which it enables, as x86 platforms are one of the systems which
use EFI boot, and while when using EFI to boot, /boot is irrelevant,
not all x86 systems use it.   If we start making distributions where
/boot is a directory, then lots of those systems are going to fail.

Of course they wouldn't if they have installed the new version of the PBR
boot blocks, but I know of lots of people who essentially never do that.
They have happily done NetBSD upgrades (major version upgrades) without
touching anything outside the NetBSD filesystems.   At least since we
stopped encoding the /boot block numbers in the PBR boot code.   The boot
blocks work, updating them to something which should work, but who knows
since this is all BIOS using code, and no-one can test against every
ancient BOIS that ever existed, is dangerous.

I am using EFI booting now, so this isn't immediately relevant directly,
but I an assure you that I was one of the people who did what I just
described, I'd never upgrade working boot blocks if there was any
alternative.

Please leave /boot as it is (on x86 and arm and anything else that uses
something of that name) and make a new standard place for mounting the ESP.
That can be /efi (which I am currently using) or anywhere else that seems
reasonable (I can easily update my fstab), just not /boot (not on arm
systems either, unless there is some very good reason that it has to be
that way, which I very much doubt - the ESP should contain nothing that
is needed while the system is running, except when there is a need to
update it - my /efi is "noauto" in fstab, and I almost never mount it).

kre