Because NetBSD already uses /boot for a different purpose, this version of
GRUB has been compiled to look in /grub for its files (specifically,
menu.lst and the loaders).  If your root filesystem is of a type not
supported directly by grub (eg, lfs), you may have difficulties.  See the
info docs for more details.

GRUB is not actually installed on your disk until you run a command such as
  grub-install /dev/wd0d
or
  grub-install '(hd0)'