Making a flasher image and stab

I am using the script in /opt/scripts/tools/eMMC to make a beagle bone black flasher image from my emmc. when I flash with that image, it seems to reset my fstab on the newly flashed beagle bone to remove my auto mount entry for the SD card. I looked at the script and noticed it seemed to use just a few commands. Is there some script I need to modify if I wanted to add the auto mount line for the SD card in my fstab?