[Nouveau] Firmware required?

[Dennis den Brok]

Dear nouveau@,

please forgive me if this is a FAQ or otherwise obvious; it isn't to me
from searching the web, the nouveau mailing list archives and various
Linux distributions' wiki pages.

I'd like to know for which nvidia GPUs a firmware binary blob needs to
be loaded to the GPU in order for nouveau to work with it, including
binaries from what is often called "linux-firmware".  Hopefully more
precisely:

Are there GPUs supported by nouveau which do not work at all without a
binary blob?

Are there GPUs which work partially without a firmware binary blob? 
What are the restrictions?

Are there GPUs which work without restrictions?

If there is a resource with answers to my questions, I'd be grateful
for a reference.

Please CC me, as I am not subscribed to the list.

Thanks and regards,

Dennis den Brok