Some months ago i bought a M3 to play with. I’ve taken the 2015-12-10-debian-8-jessie-mate-bpi-m3-sd-emmc.img and put in into the eMMC.
Now i want to play with another distribution and put it on the SD card. The problem: nothing happens on boot up (permanent red LED). I’ve tried several images, none of them seemed to work. After spending shitload of hours and no progress, I put the 2015-12-10-debian-8-jessie-mate-bpi-m3-sd-emmc.img on the sd card, plugged it in and voila: it boots.
Question 1: What would I have to change, that the M3 would boot from eMMC w/o the sd card plugged in?
Question 2: How could i properly clean up so that I could play with other images? Is
dd if=/dev/zero of=/dev/mmcblk1 sufficient? Or do I have to do anything else? Does it require me to press the uboot/FEL in order to switch the boot device order?
Question 3: I want to use the M3 as an owncloud instance - any image where this is recommended, so I don’t have to waste my rare spare time. (headless is fine)