First of all, thanks for this awesome repo! You saved my EdgeRouter today :)

I ran into the issue that the USB stick created using these scripts would not boot. Using the serial console I saw that the USB stick was too slow, so uboot aborted. Now typing usb start worked though, and thus run bootcmd worked as well.

My solution was to setenv bootdelay 10 (sadly, the delay is after trying to start usb so this alone does not work) and setenv bootcmd usb start \; followed by the rest of the bootcmd (warning: as the bootcmd contains semicolons, these must be escaped using backslash and be surrounded by spaces: \;). Afterwards, saveenv persists these settings for the next boot (but you can try them first by running run bootcmd).

On my EdgeRouter, the full uboot commands thus look like this:

setenv bootdelay 10

setenv bootcmd usb start \; fatload usb 0 $loadaddr vmlinux.64 \; bootoctlinux $loadaddr coremask=0x3 root=/dev/sda2 rootdelay=15 rw rootsqimg=squashfs.img rootsqwdir=w mtdparts=phys_mapped_flash:512k(boot0),512k(boot1),64k@1024k(eeprom)

saveenv

Now, on every boot, uboot first fails to start usb, then waits 10 seconds, then initializes USB and boots the EdgeRouter. I think I can live with that :)

Do you want a PR to add this to a Troubleshooting section in your Readme?