Ummmm .... errrr ....
I've been down the road with ethernet on an ARM. You *really* need some sort of an OS to make it do more than simple stuff. As soon as you get into a real TCP/IP "multiple packets in flight" situation things get pretty nutty with managing all the states. UDP you can do all day long with next to nothing. Simple send and forget TCP/IP (which isn't really TCP/IP) you can do easily. The real thing - not so much.
I've been down the road with ethernet on an ARM. You *really* need some sort of an OS to make it do more than simple stuff. As soon as you get into a real TCP/IP "multiple packets in flight" situation things get pretty nutty with managing all the states. UDP you can do all day long with next to nothing. Simple send and forget TCP/IP (which isn't really TCP/IP) you can do easily. The real thing - not so much.