Beginners Guide: Migrating to SSD

[SirRyanTheGeek]

Sadly none of these methods are 100% stable (yet)

I'm having issues after having tried everything in this thread, as well as using the latest SPI flash to allow for USB boot (no microSD or eMMC card). The problem is, depending on WHAT you're plugging in to the USB port, there isn't enough of a delay between startup and waiting for whatever is attached to "spin up" and be ready to boot.

I can get it to boot on USB alone on average only 1 out of every 7 to 10 attempts. And on one of these attempts it corrupted the filesystem to where I had to re-image it from scratch onto the SSD. 

What I'd like to see is if it is possible is to do one of three things:

• Use a new SPI flash that allows a programmatic timeout/delay that is somehow configurable that says something like "wait 20 seconds for anything attached to spin up - then attempt a boot if you find a bootable partition. Then it won't matter if you plug in a slow HD, fast SSD or a USB key with an OS - it should still find it and fire up and not hang
  

• Clear instructions on how to use something like what we have for the Pi - a microSD card that has nothing on it all except "bootcode.bin" bootloader and an empty file called "TIMEOUT" that forces a delay I think of 20 seconds - more than ample time to get anything USB attached to power up and be recognized
  

• Or failing any of the above - using a low-size un-important SD card, if I put the same Bionic or Stretch image on it that I do on the SSD that I plug in, what changes do i need to make to the SD card before I boot it up to just point to whatever it finds first that is attached to USB again, with a delay. Same thing as the second option listed except using the whole image as nothing but a bootloader. 
   
  

With either the second or third options, I am perfectly okay with "wasting" a cheap microSD for the purpose of knowing I will always get a reliable bootup after running a reboot or power-cycling the board.