Can't boot from USB on Asus C100

[ahillis427]

I'm totally new at this, but followed every instruction at https://archlinuxarm.org/platforms/armv ... flip-c100p

Things seemed to work well, but when I'm at the splash screen and press Ctrl-U to boot from the USB drive the screen blinks and beeps. That's it...

I have typed in the shell the "crossystem dev_boot_usb=1 dev_boot_signed_only=0" command to enable USB booting and I rebooted for changes to take effect.

My assumption was that was all I needed.
I'm a little lost.