Simple answer - run Linux on it. Your CPU and board may not have enough memory for that though.
If you don't want to do that you still need some sort of Operating System that can support a Network Stack.
At a minimum you need reliable Ethernet drivers. These are complex and hard to write, so don't try to write one your self.
Then you need an IP Protocol stack to receive and send raw IP packets. You then need at a minimum a UDP stack. That would allow communication with PCs, but you'd be better off running TCP than UDP.
So you need a complete TCP/IP protocol stack. Start searching for what's available. The "Freescale MQX Real-Time TCP/IP Communication Suite (RTCS)" might suit you.
The modern way for a device to get an IP address is to run DHCP. That's how your PCs get their IP addresses. If you're doing that you don't know what IP address the board is going to get so it will have to "advertise" itself somehow. Avahi (or whatever Apple call it) is a possibility for that. If you want the unit to have a fixed IP address then the protocol stacks all support that somehow, but you'll have to add some sort of "User Interface" to allow that address to be entered and stored.
I've spent years doing the above on a project. That wasn't a good use of my time - the company should have bought something rather than pay me to port and write large slabs of it.
Tom
