I'd like to setup several memory disk (ramdisk), but I did not find any
helpful info on the docs (sorry).
I'd like to know:
 - what are the kernel options to enable ramdisk?;
 - which are device files I need?;
 - what command to create, mk file sys. and mount?

P.S.: All I've found is for FreeBsd but seems to me inapplicable to NetBsd:
 mknod /dev/ad0a c 116 0
 mknod /dev/ad0c c 116 2
 disklabel -e /dev/ad0c and define a partition a: type 4.2BSD
 disklabel -B -r /dev/ad0c
 newfs /dev/ad0a
 mount /dev/ad0a /memory_fs

Thanks in advance,
Roberto