In March, Eye-Fi finally released source code for their copy of eCos and began complying with the GPL. Over in the message boards, Berend mentioned that nobody had ever asked for the source like that before. Citing the GPL in June 2008 in a private email I mentioned that "That's why I'm only asking for eCos itself". Oh, well. It's good to see that they're learning.
It's good to remember that this is just eCos and not the wireless driver or any of the custom Eye-Fi code that runs on the card. This is probably just what Eye-Fi got from Atheros after Atheros ported eCos to the AR6001. What this means practically is that we could probably build something to run on the card, but that the WiFi would not work. We'd have to either find some way to hack in bits of the original binaries, or find out how to operate the radio on our own.
On another front, I realized that each download of new binary firmware is unique. Even if you ask for the same firmware version and card MAC, you get a different image. The MAC or some other identifier must be recorded in the image because the card refuses to flash a new firmware unless it was downloaded with the correct MAC. Probably a "security" measure to help ensure that people do not flash the firmware for the higher end cards like the "Pro" on to the lower end cards.