Thanks for the reply.  I'm interested in trying this, but don't exactly 
understand how to do it.  Based on my interpretation of what you wrote:

I built what I think is the entire distribution, including the kernel.  
I ended up with a set of files that looked like:

~/arm-release/evbarm/binary/sets$ ls
base.tgz  comp.tgz   kern-ADI_BRH.tgz  man.tgz   SHA512     text.tgz
BSDSUM    etc.tgz    kern-IXM1200.tgz  MD5       SYSVSUM
CKSUM     games.tgz  kern-NSLU2.tgz    misc.tgz  tests.tgz

Using linux, and a thumb drive formatted with linux, I copied all of the 
above files to the thumb drive, and then expanded the non-kernel *.tgz 
files using "tar -xzvpf base.tgz", etc.  I also expanded the 
kern-NSLU2.tgz file and copied the netbsd.bin file to my tftp server.  
After rebooting the NSLU2, I saw...

[...snip...]
root device: sd0c
dump device (default sd0b): none
file system (default generic):
root on sd0c
mountroot: trying ffs...
root file system type: ffs
xrtc0: xrtc_clock_read: failed to read rtc at 0x0
xrtc0: xrtc_clock_read: failed to read rtc at 0x0
WARNING: preposterous TOD clock time
WARNING: using filesystem time
WARNING: CHECK AND RESET THE DATE!
warning: lookup /dev/console: error 20
init path (default /sbin/init):
init: copying out path `/sbin/init' 11
exec /sbin/init: error 20
[...some other suggestions instead of /sbin/init, all with the same 
degree of success...]

I was sort of surprised that the NSLU2 thought the thumb drive was ffs, 
even though it was formatted as ext2.  I also tried forcing it to use 
ext2fs (using a kernel I compiled with ext2fs support), and got the 
following.

[...snip...]
root device: sd0c
dump device (default sd0b): none
file system (default generic): ext2fs
root on sd0c
cannot mount root, error = 22
[...snip...]

Obviously less success than the previous. 
If you could give a few more details, I would greatly appreciate it.

Thanks, Don

rtos wrote:
>> At any rate, I'm going to try recompiling the kernel with ext2 support
>> and see if I can create a root USB drive from a linux machine (I don't
>> have a machine running NetBSD).  Trying to figure out SELinux seems
>> like a no-win situation, though I suppose I could always disable it.
>>
>> If somebody has a better idea, I'd appreciate hearing about it.
>>
>> Thanks, Don
>>     
>
> IMHO, for linux users that want ffs rootfs, there is an easier way to
> install the slug. No need for NFS or another NetBSD machine. 
> 1) Build the entire NSLU2 distribution including the installation
> kernel. (I had to add NSLU2 to the list of armeb targets in some
> makefiles IIRC)
> 2) Copy the distribution sets to a partition on your usb disk.
> 3) Boot the installation kernel and follow the instructions.
>
>