Booting microsd with debian after installing android to flash

[paddi]

Hello.

I've just received the olinuxino a20 with 4gb NAND. I've installed the debian image to a microsd and booted it with the initiallay hdmi output. The red and green leds were on.

Then I installed the adroid image to the nand flash. The board is booting coorectly to the android desktop with 1080p60 on HDMI. Without a touch display the android is not really sensitiv with mouses. Therefore I want to use my debian on the sd. Therefore I put the card back in the board, reset, but the board still continues booting the android from the flash. I have already reimaged the sd with the debian-image to avoid changes, but nothing changed.

How can I force the board booting the image from the uSD?

THanks for help.