Re: EFI amd64: boot.cfg goes where?

On Wed, 5 Aug 2026, DTB wrote:

> I went back over everything and made it a little further. I liked the
> sound of having a menu to be able to break into the boot prompt and boot
> single user and such, so I tweaked the example in boot.cfg(5) to work
> with my system:
>
> root=hd0d
> menu=Boot:rndseed /etc/entropy-file; boot hd0d:netbsd
> menu=Boot single-user:rndseed /etc/entropy-file; boot hd0d:netbsd -s
> menu=Boot prompt:prompt
> default=1
> timeout=3
> clear=1
>

For your simple layout (EFI with only 1 NetBSD FFS partition) you just need
something like:

```
#
# 1st NetBSD partition (index-wise) on disk--no label needed.
#
menu=Boot normally:gop 0;boot
menu=Boot single user:boot -s
#
# 2nd NetBSD system w/ label `NB_test'
#
menu=Boot TEST:gop 0;boot NAME=NB_test:
menu=Boot TEST single user:boot NAME=NB_test: -s
menu=Drop to boot prompt:prompt
rndseed=/var/db/entropy-file
default=1
timeout=10
clear=1
# userconf=disable i915drmkms*
```

That's an actual `boot.cfg' (on the 1st NetBSD / partn.--the other one isn't
read--w/o a `bootme') from when I had 2 NetBSD installs (10.x and 9.x).

> [...] I am a little curious as to how my NetBSD rootfs at GPT partition 4 is
> called hd0d by the booter as I thought hd0d would be the third partition; it
> goes hd0a, hd0b, and then hd0c is the whole drive, right?
>

You wouldn't use that `hdN[a-z]' syntax at all with an EFI partitioned disk.
You would use, here, `NAME=some_label' for device names. See `help' for the
device spec. syntax; also `2.2.2. Partitions' in the Guide.

EFI partitions show up as wedges (not slices--as in a disklabel): dk0, dk1, etc.,
and that's what you would use in `fstab' or when mounting:

```
mount /dev/rdk1 /mnt
mount NAME=msdos /mnt		# label -> devname using getfsspecname(3)
fsck -nf NAME=NB_Root		#             "
```

Just make sure the EFI label + the `NAME=' tag is < 16 bytes total.

HTH,

-RVP