Seems to me, that you're doing it right. When installed the .deb pinephone-u-boot-install should be run (a script under /usr/sbin I believe).
What got me started was this.
I have used a slightly different make command (setting env vars), maybe that's the difference?
Good luck!
What got me started was this.
I have used a slightly different make command (setting env vars), maybe that's the difference?
Good luck!