Deploy Ubuntu Beagle Bone Black Image From USB SSD using Powered USB hub

[chris....@star3.com]

I am attempting to do the following using the Beagle Bone Black Rev C:

1. Boot the Beagle Bone Black from a USB hard drive.
2. Run autorun.sh automatically to apply a Ubuntu-18.04.img.gz image file to the Beagle Board Black.
   
3. Reboot into Unbuntu after the image has been applied.

Note: My end goal is to have the Beagle Bone Black configure so it can be recovered using a .img.gz file from a USB SSD without using a micro SD card since they can be easily lost.  A micro SD card can be used to configure the board initially if necessary. 

Problems:

• Can someone recommend a way to force u-boot to start USB automatically and attempt to boot from USB SSD every time?  Note: I am using a powered USB hub.
• BuildRoot executes /etc/init.d/S99autorun and looks for the autorun.sh on a micro SD card.  Can someone recommend a way to edit this file so it points to sda1?

I have successfully completed the following using the USB serial connector:

1. Power on the Beagle Bone Black and press spacebar to abort autoboot.
2. Manually execute the following commands from uboot to boot from a USB hard drive formatted as FAT32.
• 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}
3. Execute the following commands in autorun.sh file:

• echo timer > /sys/class/leds/beaglebone\:green\:usr0/trigger
• dd if=/dev/sda1 bs=16M |gzip -c > /mnt/Ubuntu-18.04.img.gz
• sync
• echo default-on > /sys/class/leds/beaglebone\:green\:usr0/trigger
• 4. Reboot Beagle Bone Black into Unbuntu.

I downloaded the files for applying the image from the following link:

https://elinux.org/BeagleBone_Black_Extracting_eMMC_contents 

The following article mentions creating a script and running it from a micro SD card:

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