Deploying Ubuntu Image From USB SSD - Beagle Bone Black

I am attempting to do the following and I am feel like I am close:
Boot Beagle bone Black Rev C from USB SSD drive into build root.
Automatically execute autorun.sh from the USB SSD to apply Ubuntu.img.gz image file.
Reboot the Beagle Bone Black into Ubuntu.
Note: I want the capability to restore the Beagle Bone Black without using a micro SD card. I am really new to Linux.

Problems:

I can successfully boot from the USB hard drive by executing manually the following commands from the u-boot prompt, but have not successfully automated these commands. Can I update u-boot to automatically attempt USB boot?
usb start
bootpart=0:1
bootdir=/
fatload usb 0:1 ${loadaddr} /uImage
fatload usb 0:1 ${fdtaddr} /am335x-boneblack.dtb
setenv bootargs console=${console} ${optargs}
bootm ${loadaddr} - ${fdtaddr}
Buildroot is automatically looking for the micro SD card due to the /etc/init.d/S99autorun file. How do I edit this file?

I downloaded the files for Buildroot through the following link:

BeagleBone Black Extracting eMMC contents
https://elinux.org/BeagleBone_Black_Extracting_eMMC_contents

I have read the following articles, but have been unable to put all of the pieces together.

Beaglebone Black Booting From USB
https://groups.google.com/forum/#!searchin/beagleboard/boot$20beagle$20board$20from$20usb$20hard$20drive|sort:date/beagleboard/iznBJnxa-AU/Ezt1-bYQBgAJ

USB hard drive booting
https://groups.google.com/forum/#!searchin/beagleboard/boot$20beagle$20board$20from$20usb$20hard$20drive|sort:date/beagleboard/9T6feUimWR4/FJpcL5StIHUJ

http://lumpynose.wordpress.com/2014/02/10/beaglebone-black-usb-hard-drive-boot-setup-draft/

I can successfully boot from the USB hard drive by executing manually the
following commands from the u-boot prompt, but have not successfully
automated these commands. Can I update u-boot to automatically attempt USB
boot?
usb start
bootpart=0:1
bootdir=/
fatload usb 0:1 ${loadaddr} /uImage
fatload usb 0:1 ${fdtaddr} /am335x-boneblack.dtb
setenv bootargs console=${console} ${optargs}
bootm ${loadaddr} - ${fdtaddr}

Your easiest bet would be to have a small boot-strap MicroSD card that
has U-Boot configured to boot from USB.

U-Boot stores its configuration in environment which can be persisted to
an EEPROM or disk/SD card partition, not sure how the BeagleBoard
instances are set up in this regard.

If you run `printenv` you'll see all the variables that are set.
`setenv` modifies a variable, and `saveenv`, saves the current set of
variables to that non-volatile storage volume.

The U-Boot Documentation — Das U-Boot unknown version documentation documents all the
variables. Many of these you'll see are "scripts" which are executed
with the `run` command.

If the persistent storage is set up, you should be able to configure
U-Boot, then run `saveenv` to store the configuration -- rebooting
should have the board run your commands automatically.

Failing that, you'll need to re-compile U-Boot with the appropriate
default environment settings -- doable, but you risk bricking the board
if something goes wrong.

Buildroot is automatically looking for the micro SD card due to the
/etc/init.d/S99autorun file. How do I edit this file?

I'd imagine running `sudo -s` then using `${EDITOR}
/etc/init.d/S99autorun` to modify the file.