USB mass storage boot on armv7 RPI2

For some time it was possible to boot a pi2 using a normal
FreeBSD image on a USB storage device by placing on the microSD
DOS partition only bootcode.bin and an optional timeout file.

That seems to no longer work, as of a few days ago on -current.

If anybody can shed light on the puzzle it'd be much appreciated.

Also, the version of u-boot furnished with FreeBSD allowed
escape to the u-boot prompt, followed by
usb reset
and 
run bootcmd_usb0
which seems to have gone away. U-boot does report having a
usbboot command, but it reports

U-Boot> usbboot
** No device specified **
U-Boot>

Running 
help usbboot reports
 
usbboot - boot from USB device

Usage:
usbboot loadAddr dev:part
U-Boot> 
usbboot - boot from USB device

If somebody can point me to the correct parameters that 
would help greatly.

Thanks for reading,

bob prohaska