Hello Ivan and Nico,
thanks for your answers. That clarified a lot. I still have some questions:
Being a closed source this firmware may contain the backdoors or help the backdoor-like functionality of intel me. So yes, this is a privacy concerning thing.
Well, don't use modern controllers (ethernet, USB, etc.) if you don't want proprietary firmware in them. But that's far from the original question...
To sum it up, I have 4 possibilities: 1. Live without ethernet firmware and without internet 2. Use the untrusted ethernet firmware with a small risk in terms of security/privacy 3. Don't use the ethernet firmware and only use a free miniPCIe Wifi card? Is this possible? 4. Don't use the ethernet firmware and only use a free USB Wifi stick
Also worth to mention, you don't have to add this file or any related file (ME, IFD) into coreboot. This option is only for people that want to put everything into a single file to flash at once. You can instead just write coreboot only, to the respective BIOS region in flash. And leave everything else intact.
But than I can't disable Intel ME and can't use me_cleaner? If I read correctly: when you disable Intel ME, you have to insert IFD and GbE into coreboot? Btw, do I also have to insert EC firmware than?
Greetings