Adding modprobe.blacklist-nouveau, I have the exact same error.
Passing nouveau.modeset=0, I have a blinking _ with no text.
Adding nouveau.modeset=o nomodeset and systemd.unit=multi-user.target allows me to boot to tty1. When I tried running startx from there, I got
Fatal server error: (EE) no screens found(EE) (EE) Please consult the X.Org Foundation support
along with some other information, after which it wrote
xinit: giving up xinit: unable to connect to X server: Connection refused xinit: server error