This is how I created the missing u-boot.scr for my odroidxu with debian_jessie_armhf_odroidxu_20130927.img flashed to eMMC.
You need the tools and know-how to generate a u-boot script from a text file source:
Attach eMMC or SD-Card to your Linux host and note the mount point and drive designation. Mine will be different from yours. If you already flashed the image, you probably don't need much help on this item.
# go to the mounted vfat directory of mounted media on your host # My volume label happens to be as shown: cd /media/6E35-5356 # Use the uboot utility to compile the default boot script template mkimage -T script -A arm -C none -n 'Boot script for odroidxu' -d boot.ini boot.scr # Always sync sync # move up cd .. # replace the X with your drive designation (hint: do dmesg and see what the latest mount was ) sudo umount /dev/sdX*
Now plug the media back in to odroid and power up