beaglebone automatically boots from sd

I have installed Ubuntu in the eMMC of the BeagleBone Black and Debian “bone-debian-7.8-lxde-4gb-armhf-2015-03-01-4gb.img” on the SD (non flasher).

If I remove the SD card only I am able to boot from the eMMC. If I boot while the SD is plugged with no switched pressed the BBB boots by default the SD image. Also if I boot (connect power cable) while holding the boot switch still BBB boots from the SD card.

Why does this happen? Has anyone else had this experience?

It's Magic!

It's way we have it setup...

Regards,

The u-boot programming (see uEnv.txt or stop during boot and say printenv) will show you that it first probes if there is a bootable SD card inserted and in such a case it boots from SD card.
If you don’t want this, you need to change settings in uEnv.txt

Thanks everyone!