I cannot get my machine to boot without my USB.

[BSDguru]

Just to update, I did find how to copy to the EFI partition on the hard drive. The trick is no boot flags at all. More is less, apparently.

 

[Artbucks]

This may have been a helpful tip for my Asus Z170-A ATX DDR4 board. "In the UEFI do you have CSM set to Auto and the Boot Devices Control set to UEFI only? This is the proper setting for OS X on Asus boards." Although it did not solve my booting problem. It still gets about as far as the progress bar in my user icon. Still need help booting.