Boot sequence

Assumed there is no eMMC available on BBB, would it boot from SD-card automatically as first boot device?

Assumed there is no eMMC available on BBB, would it boot from SD-card
automatically as first boot device?

yes

From my understanding this is what BeagleBone White does - but are there any
more differences than just the eMMC to let it boot in an other order?

page 6 of 11, sysboot pins 4:0 control the peripheral boot sequence from rom.

Regards,

Yes it would. This is all documented in the SRM.

http://www.elinux.org/Beagleboard:BeagleBoneBlack#LATEST_PRODUCTION_FILES_.28C.29

Gerald