This HOW-TO should make it easy for anyone to load and run NetBSD on a 
PogoPlug without having to disassemble the device and solder on a serial 
adapter. If you won't be using a serial port, skip the next part.

Pins on the PogoPlug (Mobile and Series 4) are numbered one through four 
immediately behind the SD card (where behind means towards the rear where 
the plugs are). One is farthest back and four is closest to the SD card 
slot. TxD is really transmit and RxD, receive. Connect at 115200 baud.

1: power (3.3 volts)
2: TxD
3: RxD
4: ground

If you're not using a serial connection, you'll have to create an account 
at http://my.pogoplug.com/, activate the device at 
http://my.pogoplug.com/, then navigate to Settings (starting with the tiny 
gear icon in the top right of the web interface), select Security, then 
enable ssh for your PogoPlug. Choose your own ssh password. Then, ssh as 
user root to the IP of your PogoPlug.

Connect ethernet to a network where the PogoPlug can get a DHCP lease and 
access to the Internet. Either with a serial console or via ssh, you're at 
a root prompt. Paste in these lines to get tools and the NetBSD kernel.

cd /tmp
wget http://download.doozan.com/uboot/nandwrite
wget http://download.doozan.com/uboot/flash_erase
wget http://ftp.netbsd.org/pub/NetBSD/misc/jklos/netbsd.pogo
chmod +x nandwrite flash_erase

If you like, you can get nanddump (via wget 
http://download.doozan.com/uboot/nanddump) and back up mtd3 before 
overwriting and scp it somewhere else. Something like this would work:

./nanddump  -f pogov4mtd3.dump -o /dev/mtd3

Now we flash the actual NetBSD kernel. mtd3 is labeled "failsafe" in the 
mtd map and is 8 megs from the start of flash and 8 megs long. The block 
size on the PogoPlug is 131072 bytes, so 64 blocks of 128k each works out 
to 8 megs. The "-p" option of nandwrite is to pad the kernel to fit whole 
blocks.

./flash_erase /dev/mtd3 0 64
./nandwrite -p /dev/mtd3 netbsd.pogo

Next, we write the environment variable bootcmd. Note that the mw commands 
in the beginning are necessary so that NetBSD can use the SD card slot. 
Enter the following as one continuous line (keep spaces where it wraps):

/usr/local/cloudengines/bin/blparam bootcmd='mw f1010004 11113311; mw 
f1010008 551111; if ping 192.168.58.254; then run boot_nand; fi; nand 
read.e 0x800000 0x800000 0x500000; bootm 0x800000'

For PogoPlug Pink, the beginning of mtd3 is 0x2500000, so use:

/usr/local/cloudengines/bin/blparam bootcmd='if ping 192.168.58.254; then 
run boot_nand; fi; nand read.e 0x800000 0x2500000 0x500000; bootm 0x800000'

Note that the kernel's current size is 4380032 bytes (but it may change, 
so please check), or 0x42d580 in hex, so we can round up to 0x500000 in 
the nand read.e command like so. If you make a custom kernel, be sure to 
make sure the read.e command loads the entire kernel.

nand read.e 0x800000 0x800000 0x500000

We decide whether to boot NetBSD or GNU/Linux based on whether we can ping 
a machine on the network so we can download and flash a new kernel using 
GNU/Linux, if we like, without a serial console. Creating an alias is as 
simple as something like:

ifconfig usmsc0 inet 192.168.58.254 netmask 0xffffff00 alias Once back in 
GNU/Linux, you can rerun the above but with a new kernel or your own 
custom kernel. A sample kernel configuration file for NetBSD-current is 
here:

http://ftp.netbsd.org/pub/NetBSD/misc/jklos/POGO

These notes can also be found here:

http://ftp.netbsd.org/pub/NetBSD/misc/jklos/pogoplug_notes

You can use another NetBSD machine to install NetBSD to an SD card and 
the kernel you just installed will use that as the root filesystem. A link 
for a quick NetBSD installation how-to will come soon.