RVP <r...@sdf.org> wrote:
> On Sat, 5 Jul 2025, beaker wrote:
>
> > I'm having trouble setting up GRUB2 chainloader booting of a NetBSD system.
> >
>
> Here's my working GRUB config on my home laptop:
>
> ```
> $ cat /etc/grub.d/40_custom
> #!/bin/sh
> exec tail -n +3 $0
> # This file provides an easy way to add custom menu entries. Simply type the
> # menu entries you want to add after this comment. Be careful not to change
> # the 'exec tail' line above.
>
> menuentry 'FreeBSD 14.2' --class freebsd --class bsd --class os
> $menuentry_id_option 'freebsd' {
> search --efidisk-only --fs-uuid 42F8-14F2 --hint hd0,gpt6 --set root
> chainloader /efi/boot/bootx64.efi
> }
>
> menuentry 'NetBSD HEAD' --class netbsd --class bsd --class os
> $menuentry_id_option 'netbsd' {
> search --efidisk-only --fs-uuid 7AB0-0BFD --hint hd0,gpt9 --set root
> chainloader /efi/boot/bootx64.efi
> }
>
> menuentry 'OpenBSD 7.6' --class openbsd --class bsd --class os
> $menuentry_id_option 'openbsd' {
> search --efidisk-only --fs-uuid C8D7-D5E8 --hint hd0,gpt13 --set root
> chainloader /efi/boot/bootx64.efi
> }
>
> menuentry 'rEFInd' --class openbsd --class bsd --class os
> $menuentry_id_option 'refind' {
> search --efidisk-only --fs-uuid C8D7-D5E8 --hint hd0,gpt13 --set root
> chainloader /efi/refind/refind_x64.efi
> }
> $
> ```
>
> The only tricky part is figuring out the `--fs-uuid' value. Use `lsblk -f' on
> Linux to get this. (It's _not_ any of the GPT GUIDs.) As you can see, I have
> separate EFI ESP partitions for each of the OSes.
>
> HTH,
Thanks but my system isn't UEFI so I think this won't work but I'll
squirrel this away for future reference.
I think Elst's comment is right, that there isn't actually a primary
NetBSD bootloader present on the referenced partition so one needs
to be installed, though I'm unsure how to do this with non-UEFI gpt
partitioning; do I use gpt(8) or installboot(8) and where to install
it? If I install it to gpt6 (bios) partition is wipes out GRUB (know
this from experience...), but if I install it on gpt3 (FFS) is it
going to mess up the existing file system?
Think I'll need to dig out an old laptop and do some more testing.
-B
