boot device: <unknown> with inkernel root file system on evbarm

["Marcin M. Jessa" <lists%yazzy.org@localhost>]

Hi guys.

I have compiled a custom IXDP425 kernel with among others following 
definitions:
config          netbsd          root on md0a type ffs dumps on none

# disk/mass storage pseudo-devices
pseudo-device   md              1       # memory disk device (ramdisk)
options         MEMORY_DISK_HOOKS       # enable root ramdisk
options         MEMORY_DISK_ROOT_SIZE=20480     # Size in blocks - 10M - 
10*1024*2
options         MEMORY_DISK_IS_ROOT     # use memory disk as root

I have also created a small root file system, created a file system 
image and inserted it to my ELF kernel:
# du -hs boot/
7.1M    boot
# makefs -s 10240k -t ffs md.img boot/
# mdsetimage -v -s netbsd md.img

Booting this kernel I get following output:
clock: hz=100 stathz=0 profhz=0
boot device: <unknown>
root on md0a
cannot mount root, error = 22
root device (default md0a):

I'm on NetBSD 5.99.24.

Why isn't the boot device recognized? Am I forgetting something here?


Marcin