Re: GRUB2 chainloading GPT NetBSD partition

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

    Date:        Tue, 08 Jul 2025 16:45:52 -0700
    From:        beaker%sdf.org@localhost (beaker)
    Message-ID:  <686dadb0.P/8mOw8RkRIc1DEj%beaker%sdf.org@localhost>


  | It's not an msdos partion AFAIK but dkctl(8) lists it like that:

You should fix that, it is set to be an EFI partition, which would
confuse EFI firmware, if the drive was ever installed in a system
which uses that, just

	gpt type -i 3 -T ffs wd0

should change its type to be a NetBSD FFS partition type.   (EFI
partitions are a specially standardised version of Microsoft FAT
partitions, which in NetBSD we call "msdos" type - that works for
both EFI and regular Mircosoft FAT partitions).

So:

  | dk2: NetBSD, 125829120 blocks at 269486080, type: msdos

type msdos there (what the kernel would treat it as by default).

 125829120      3  GPT part - EFI System
  |                                  Type: efi
  |                                  TypeID: c12a7328-f81f-11d2-ba4b-00a0c93ec93b
  |                                  GUID: 7ad533d2-4cdc-4de7-86b7-712fc0c449c0
  |                                  Size: 61440 M
  |                                  Label: NetBSD
  |                                  Attributes: None

And type efi there (what's actually in the GPT partition label).

  | Also AFAIK the primary bootstrap code is still installed on gpt3 (rdk2).


Yes, it would be, nothing you would rationally ever do to a working
filesystem will remove that, nor is there any need.

It seems, from what Michael said in an earlier message (which wasn't
cc'd to you) that RVP was right, to boot currently various ugly hacks are
needed, which grub is (understandably) not doing.

That is, you will eventually need a replacement for that bootstrap
code ... but someone has to write it first!   It should be possible,
and it needs doing (just not by me, I don't understand PC architecture
nearly well enough to even come close to getting it correct.)

For now, I'd suggest you just keep booting NetBSD via the method that
works, until there is something better available.

kre