There is a SATA interface though. A user would need the right cable, a third party case or modding the standard enclosure. A friend of mine has taken a SATA to mSATA board adapter (like this one), fixed it on a wood frame with the APU next to it, cut the case to let the cable out and screwed the whole thing on the wall. Then, on the firmware the order of the boot load is first the external mSATA and then the internal one. When he wants to boot from the external disk, he just needs to connect the cable.