Blacklist the nouveau driver like this:
- mount -o remount,rw /flash
- Open the config file by editor with nano /flash/syslinux.cfg
- Edit the append line like this:
- Store the config file by key combo STRG + O
- Leave the editor by key combo STRG + X
If this doesn't work, try nouveau_init instead of nouveau at the append line.
It's not tested by me, I'm just an RPi user.
Sorry for the late response, that seems to work thanks!
So HDMI seems to work without any modifications as long as the laptops lid is closed. When the lid is open and the internal screen is on, there's no output on any of the ports. If I reboot and close the laptop, HDMI and Display Port are working. By blacklisting nouveau in syslinux I can boot the laptop even with the laptop open and the internal screen on, it outputs though HDMI & DP once booted.
I've been a Raspberry Pi user for years, it just sucks my Rpi3b+ can't handle H265 and I don't want to buy a rpi4 or a TVbox.