How to force boot from SD Card??

OK, first let me apologize if this has been answered several times before.

I have a stripped beaglebone black that boots from SD card. When I mean stripped it does NOT have eMMC, USB Client, reset button, HDMI Framer, boot button, micro HDMI, USB Host and more missing. Like I said it boots from SD card. It is running Angstrom GNU/Linux v2013.06 (Core edition) version 3.8.13

So I have another Full blown BBB with nothing missing. It is running Angstrom GNU/Linux version 3.8.13-00726-gbe46145-dirty from the eMMC.

What I want to do is take the SD card from the stripped BBB and boot from it in the Full BBB, When I try this, it still boots from the eMMC and not the SD card.

Any suggestions/Ideas to try?? Thanks

Push and hold the "boot" button before you apply power..


Great, thank you. Anyway to make that a permanent solution?

Option a:
erase eMMC

Option b:
understand eMMC's u-boot..


If the eMMC is not there, it should boot from the SD card by default, assuming you have left all the boot resistors in their default configuration…



Or if you are a hardware guy and you can work with small SMD components, you can also change the SYS_BOOT configuration as shown on Page 6 of the BBB schematics. In essence, move R68 to R93. This will be the equivalent to pressing the boot button.


OK, this sure looks easy, but I know I have trying to skip a couple steps or maybe not at all because it does not work for me.

I took an image of my SD card that was running in the BBB without eMMC.
I took that image and tried to use it to write to the eMMC, but it did not work.
Here is the guide:

If I am missing a simple step please let me know,

(I have tried to delete or rename the MLO file so this will auto boot from SD, but when I boot by connecting to the micro usb no media drive shows up)
Or any simple way to delete the eMMC?