"Q: How are you going to write a GPL driver by signing an NDA?
Is it going to require a binary blob or some other way of
obfuscating the code?
"A: No, not at all. I have written many drivers after signing
NDAs with companies. They are usually signed either to keep
information about the device private until it is announced at a
specific date, or to just keep the actual specification documents
from being released to the public directly. All code created by
this NDA program is to be released under the GPL for inclusion in
the main kernel tree, nothing will be obfuscated at all..."