It's looks like the one olimex is selling.
Actually I don't know if it's compatible with free/libre software but I know
that olimex does not make 100% free software hardware.
For example I have found out that blobs are needed for the NAND to work same
thing with mali, but that olimex does not explain it.
You can buy a usb to Ethernet adapter here (but they are currently out of
stock)
and by using this link 25% of the money goes to the Trisquel project.
http://libre.thinkpenguin.com/
And you can look here they are already several ones that are sure to work
https://h-node.org/ethernetcards/catalogue/fr/1/1/undef/undef/yes/USB/ethernet-works/undef
