I actually wanted to publish the instructions in a new thread in the forums and this is the best place to do it I guess.
I’ve made a small script to change the boot order for you, it’s available here : https://www.dropbox.com/s/6o2mk1ajt8r99l1/bootorder.tar.gz?dl=0
Just run change_bootorder.sh as root:
sudo sh change_bootorder.sh
MAKE SURE you don’t interrupt the process once it starts flashing coreboot, and make sure you have enough battery left and you are connected to the power supply, in case of a blackout.
This should technically work on any OS, but I’ve only tested it on PureOS. I’ve built flashrom without ftdi support so you won’t have to worry about that dependency, and this version of flashrom has skylake support (which isn’t available in the latest release of flashrom).
It should be 99.9999999% safe, but as usual, standard disclaimer applies (“provided AS IS, we are not responsible for any damage this might do to your hardware”, etc).
This is a much simpler/limited script compared to the more complete ‘purism-librem-coreboot-updater’ script, but that script only supports librem 13 v1, and I haven’t finished adding librem 13 v2, and librem 15 v3 support to it, but once I do, it will become more mainstream, a single tool to update coreboot or change the boot order, and neutralize the ME, etc…