Thanks Maechal,

With PowerBook G4, 
Sales order# M8362J/A
with Gigabit Ethernet, 550MHz version, (2001/11 or arround version)
Open Firmware 3,3 4.2.6f1 BootROM built on 09/11/01 at 16:01:17

with daily snapshot of:
  ftp://releng.netbsd.org/pub/NetBSD-daily/200206090000/macppc/

boot hd:14,ofwboot.xcf hd:14/netbsd.GENERIC_MD.gz
...
panic: lockmgr: pid 0, not exclusive lock holder 1008730331 unlocking
Stopped in pid () at   0x0a0f338:	lwz r0,r1, 0x14
db> (unable to type in)


By the way, I needed to adhere hd:14 for the boot file.
Neither
  boot hd:,ofwboot.xcf netbsd.GENERIC_MD.gz
nor
  boot hd:,ofwboot.xcf hd:14/netbsd.GENERIC_MD.gz
will find boot file properly. 
(They start secondary boot loader = ofwboot.xcf but ...)
---
Makoto Fujiwara, 
Chiba, Japan, Narita Airport and Disneyland prefecture.