RPi2B and FreeBSD 11-STABLE boot failure

[Trevor Roydhouse]

I installed:

FreeBSD rpi2.sentry.org 11.2-STABLE FreeBSD 11.2-STABLE #0 r336133: Mon 
Jul  9 20:12:49 UTC 2018 
root at releng2.nyi.freebsd.org:/usr/obj/arm.armv6/usr/src/sys/RPI2  arm

and my RPi2B could no longer boot when the two USB memory keys were also 
plugged in.

The sdcard kept being assigned as disk2, with the USB memory keys taking 
up disk0 and disk1, and then the system would unsuccessfully try booting 
  from disk0 and finding no kernel file as that happened to be the /usr 
file system.

After much google-fu, the workaround I found was to halt the boot at the 
uboot loader prompt (you have two seconds) and then:

setenv loaderdev disk2
saveenv
boot

The above creates a persistent uboot.env file, so no manual intervention 
is needed again (unless the number of USB memory keys changes).

It used to work previously without this workaround <shrug>.