I'm having problems getting freebsd to run off an external hard drive instead of the pi's SD card..
I've installed freebsd onto the pi3's SD card. The image used is FreeBSD-aarch64-12.0-GENERIC-320422M which seems to work OK.
However, I really want the system to run from a USB hard drive. So I've copied over (dump -f- | restore -rf- ) the entire installation onto a spare partition (da0p2) on an external drive (that already contains a running raspbian: a similar procedure worked happily for that!).
I've edited the fstab on both the SD card and the HD to reflect the new root system. (Not sure which of the two kernels will be used, but that doesn't matter so much).
The system starts to boot, but the loader gives expected messages about umass0 followed by da0, then stops with
"mounting from /dev/da0p2 failed with error 19"
(device does not support operation??) and waits for a manual entry of the root device.
I simply enter ufs:/dev/da0p2 and the boot finishes successfully.
I'm totally unclear about the boot process on i386, and all the more so with u-boot.
Is there something else I should be doing to set the boot device to something other than the SD card? Manual input isn't so good in the long term :-{
TIA.