These instructions are to use an SD card as extra storage on your beaglebone black. The beaglebone boots from internal memory and has micro SD card available for storage.
I used a Ubuntu operating system (running inside Virtual Box) to format the SD card and create the uEnv.txt file that tells the BBB not to use it as a booting device, but as external storage. My host comuputer operating system is Windows 7.
A. Format the SD card – Follow these steps
B. Create uEnv.txt on SD card
1. Open the the volume with the file explorer and create a new file in it named uEnv.txt
2. Right Click > Create Document > Empty File
3. Open uEnv.txt and fill it with the following 4 lines of code:
mmcdev=1 bootpart=1:2 mmcroot=/dev/mmcblk1p2 ro optargs=quiet
C. Configure beaglebone to attach SD card on boot
1. Insert microSD in beaglebone and open ssh terminal, connect to beaglebone
2. nano to /etc/fstab file. You might need to provide chmod administrative write access for the file
3. Add the following line of code to the file
/dev/mmcblk0p1 /media/card auto auto,rw,async,user,nofail 0 0
D. Restart beaglebone