Raspi3 change to usb boot

If the device fails to respond after this maximum timeout, it is possible to increase the timeout to five seconds using program_usb_boot_timeout=1 in config.txt



enable usb:

insert in cmdline.txt und boot up twice:
#enable usb boot

program_usb_boot_mode=1


Check for correct setting:

$ vcgencmd otp_dump | grep 17:
17:3020000a