Re: 24.3. Updating Bootcode

From: Nuno Teixeira <eduardo_at_freebsd.org>
Date: Tue, 16 Aug 2022 12:01:40 UTC
Hi Toomas,

For better OS support, the UEFI specification (UEFI 2.8A Feb 14, page 499)
> is suggesting to use structure like:
>
> <ESP>/efi/<OS>/…
>
> And to use this suggestion, it means the UEFI Boot Manager needs to be
> configured (see efibootmgr(8)).
>
> Therefore, once you have set up OS specific setup, there is no use for
> default (<ESP>/efi/boot/…) and you need to update one or another, but not
> both.
>

FreeBSD have <ESP>/efi/freebsd/... but it's not configured in efibootmgr:

efibootmgr -v:
---
BootOrder  : 0004, 0000, 2002, 2003, 2001
Boot0004* Windows Boot Manager
HD(1,GPT,8c497825-1db2-41f8-8924-85dfd0bb7283,0x800,0x82000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)
                                   da0p1:/EFI/Microsoft/Boot/bootmgfw.efi
(null)
+Boot0000* EFI Hard Drive (SAMSUNG MZVLB1T0HBLR-000L2)
PciRoot(0x0)/Pci(0x1d,0x0)/Pci(0x0,0x0)/NVMe(0x1,39-f9-b8-01-81-38-25-00)/HD(1,GPT,73acd1b2-de41-11eb-8156-002b67dfc673,0x28,0x82000)
 Boot2002* EFI DVD/CDROM
 Boot2003* EFI Network
 Boot2001* EFI USB Device
---
so boot is definitely using <ESP>/efi/boot/bootx64.efi @Boot0000

I think I can create a new boot:
---
efibootmgr -a -c -l /boot/efi/efi/freebsd/loader.efi -L FreeBSD-14
(and make it active)
efibootmgr -a -b NNNN
---
and create other for loader.efi.old in case of problems.

In this case I will need only update <ESP>/efi/freebsd/loader.efi.

Q: for what has been said in mailing, boot is compiled in /usr/src/stand,
isn't a good idea that when it install new boot it backup old boot like
/boot/kernel -> /boot/kernel.old?

Thanks,

-- 
Nuno Teixeira
FreeBSD Committer (ports)