Install nanobsd on Soekris net6501
I had trouble to boot from USB with nanobsd image. Here is the solution!
First you need to know that the Soekris net6501 comes default with com port at 19200 bps, so connect your console and set you computer to that speed and start the net6501.
Shortly after the boot, you'll see a count down, when asked hit CTRL+P during the count down. You will be in the BIOS config. We'll change the baud rate to be compatible with the pfSense default.
Type the following commands
set conspeed 9600 reboot
Then change the setting of your console to 9600 baud and you should see the BIOS and pfSense booting.
Now comes the tricky part of telling pfSense to wait for USB to initialize before trying to mount the USB partition.
You need to let the thing boot a little bit you'll see
1 pfSense 2 pfSense F6 PXE Boot: 1
Then you'll see
Wait until you see, be quick this thing is fast!
Then press the SPACE bar many, many time until you see
Type '?' for a list of commands, 'help' for more detailed help. OK
Delete the space you made after the message appear and type the following
set kern.cam.boot_delay=10000 boot
You should be good to go
After you get to the WebGUI you'll have to add the following line in the file /boot/loader.conf.local. Use the Diagnostic -> Edit File to do so.
I hope this helps!