I build a device with the PI 3 where only the SD card shall be accessible from outside. I plan to boot from that card (GPIO22-27). In the boot flow description it is mentioned that it is possible but not enabled:
"It is possible to boot from the secondary SD card on a second set of pins, i.e. to add a secondary SD card to the GPIO pins. However, we have not yet enabled this ability."
-> Are there plans to enable booting from the secondary SD? Shall I write an Issue?