To make a clean start on this thread I've turned on the UART for bootcode.bin per Mark's instructions and done a few boot attempts with the USB2 and USB3 mechanical disks, singly and in unison.
The bootlogs are in http://www.zefox.net/~fbsd/rpi2/bootproblems/ An immediate curiosity is that on the first try, booting with the USB3 device alone worked. I didn't record that output, unfortunately. The second attempt failed, as expected, and is recorded in bootlog-fail. The third attempt booted both USB2 and USB3 disks together, recorded in bootlog.success. I'm trying to build u-boot-rpi2 and will try to update the USB3 disk with it once complete. The actual boot sequence using bootcode.bin is still a bit hazy: Is it microSD/dos -> USB/dos ->USB/freebsd ? Thanks for reading! bob prohaska
