This has been happending for at least a week;  I haven't had time
to look at it to figure out what I'm doing wrong until today.
(I don't know what I'm doing wrong :)

A kernel from last night's sources panics when if gets to ifconfig,
which is circa 1.6.  (might be from 1.6_BETA4):

0 > boot netbsd-new -s 
>> NetBSD/macppc OpenFirmware Boot, Revision 1.2
>> (matt@duel.local, Sat Apr  7 18:09:48 PDT 2001)
no active package3178048+304640 [111+181296+150688]=0x3a380c
 start=0x100000
[ using 332748 bytes of netbsd ELF symbol table ]
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
    The NetBSD Foundation, Inc.  All rights reserved.       
Copyright (c) 1982, 1986, 1989, 1991, 1993           
    The Regents of the University of California.  All rights reserved.
                                                                      
NetBSD 1.6M (PEER) #1: Tue Jan 21 11:47:26 PST 2003
    riz@random.tastylime.net:/usr/obj/sys/arch/macppc/compile.macppc/PEER
total memory = 192 MB                                                    
avail memory = 168 MB
using 2483 buffers containing 9932 KB of memory
no active packagemainbus0 (root)               
cpu0 at mainbus0: 604ev (Revision 2.2), ID 0 (primary)
cpu0: HID0 8090c084<EMCP,DOZE,DPM,ICE,DCE,SGE,BHT>    
bandit0 at mainbus0                               
pci0 at bandit0 bus 0
pci0: i/o space, memory space enabled
pchb0 at pci0 dev 11 function 0      
pchb0: Apple Computer Bandit Host-PCI Bridge (rev. 0x03)
ohci0 at pci0 dev 13 function 0: Opti RM861HA (rev. 0x10)
ohci0: interrupting at irq 23                            
ohci0: OHCI version 1.0, legacy support
usb0 at ohci0: USB revision 1.0        
uhub0 at usb0                  
uhub0: Opti OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered              
ex0 at pci0 dev 14 function 0: 3Com 3c905B-TX 10/100 Ethernet (rev. 0x24)
ex0: interrupting at irq 24                                              
ex0: MAC address 00:10:5a:a7:4f:91
exphy0 at ex0 phy 24: 3Com internal media interface
exphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
obio0 at pci0 dev 16 function 0: addr 0xf3000000            
esp0 at obio0 offset 0x10000 irq 12: NCR53C94, 25MHz, SCSI ID 7
scsibus0 at esp0: 8 targets, 8 luns per target                 
mc0 at obio0 offset 0x11000: irq 14,2,3: address 00:a0:59:04:a1:e3
zsc0 at obio0 offset 0x13000: irq 15,16                           
zstty0 at zsc0 channel 0 (console)     
zstty1 at zsc0 channel 1          
awacs at obio0 offset 0x14000 not configured
swim3 at obio0 offset 0x15000 not configured
adb0 at obio0 offset 0x16000 irq 18: 0 targets
aed0 at adb0 addr 0: ADB Event device         
mesh0 at obio0 offset 0x18000 irq 13: 50MHz, SCSI ID 7
scsibus1 at mesh0: 8 targets, 8 luns per target       
nvram0 at obio0 offset 0x1d000                 
bandit1 at mainbus0           
pci1 at bandit1 bus 1
pci1: i/o space, memory space enabled
pchb1 at pci1 dev 11 function 0      
pchb1: Apple Computer Bandit Host-PCI Bridge (rev. 0x03)
ofb0 at pci1 dev 15 function 0: cannot map framebuffer  
IPsec: Initialized Security Association Processing.   
scsibus0: waiting 2 seconds for devices to settle...
scsibus1: waiting 2 seconds for devices to settle...
sd0 at scsibus1 target 0 lun 0: <IBM, DCAS-34330, S65A> disk fixed
sd0: 4134 MB, 8205 cyl, 6 head, 171 sec, 512 bytes/sect x 8467200 sectors
sd1 at scsibus1 target 1 lun 0: <SEAGATE, ST32171N, 0338> disk fixed     
sd1: 2061 MB, 5168 cyl, 5 head, 163 sec, 512 bytes/sect x 4222640 sectors
cd0 at scsibus1 target 4 lun 0: <PIONEER, CD-ROM DR-U06S, 1.05> cdrom removable
boot device: sd1                                                               
root on sd1a dumps on sd1b
root file system type: ffs
Enter pathname of shell or RETURN for sh: 
We recommend creating a non-root account and using su(1) for root access.
# Tue Jan 21 20:14:32 GMT 2003
swapctl: adding /dev/sd1b as swap device at priority 0
Starting file system checks:
/dev/rsd1a: file system is clean; not checking
/dev/rsd1g: file system is clean; not checking
Setting tty flags.
Setting sysctl variables:
kern.mbuf.nmbclusters: 1024 -> 4096
Starting network.
Hostname: mac.tastylime.net
IPv6 mode: host
Configuring network interfaces: ex0trap type 200 at 1759e8
panic: trap                                               
Stopped in pid 68.1 (ifconfig) at       cpu_Debugger+0x10:      lwz     r0, r1, 0
x14
db> trace
0xd49f0b50: at panic+174
0xd49f0c10: at trap+904 
0xd49f0c40: kernel MCHK trap by mii_bitbang_readreg+108: srr1=0x49030
            r1=0xd49f0cf0 cr=0x24004002 xer=0 ctr=0                  
  <?>  : at mii_bitbang_readreg+f8                 
0xd49f0cf0: at mii_bitbang_readreg+8c
0xd49f0d10: at ex_mii_readreg+70     
0xd49f0d20: at ukphy_status+50  
0xd49f0d40: at mii_phy_status+18
0xd49f0d50: at exphy_service+cc 
0xd49f0d60: at mii_pollstat+4c 
0xd49f0d70: at ex_media_stat+2c
0xd49f0d80: at ifmedia_ioctl+130
0xd49f0da0: at ex_ioctl+70      
0xd49f0dc0: at ifioctl+764
0xd49f0e10: at soo_ioctl+168
0xd49f0e20: at sys_ioctl+378
0xd49f0ee0: at syscall_plain+110
0xd49f0f50: at s_sctrap+124     
db> reboot
syncing disks... 

(never actually completes the reboot, which is annoying, because
I have to power cycle it, and the machine is about 50 miles from
where I live.  :(  )

Is there anything else I can do to track this down?  I was hoping
to move this system to -current...

Other possibly relevant details:  it's a Power Computing Power Tower Pro
with 200MHz 604e, 192M RAM, and OF 1.0.5.

Thanks,

+j
-- 
Jeff Rizzo                                         http://boogers.sf.ca.us/~riz