[lwip-users] lwip UDP. ( newbie questions )

[SergeV]

Hello. 
Few questions from a newbie. (I beg your pardon)

1) Rawapi.txt document state that
- etharp_init()
Initializes the ARP table and queue.

I believe it does nothing, should not be called (anymore) and removed from the 
doc.
Am I correct?

2) I must call periodically etharp_tmr() and tcp_tmr() if I need TCP.
I need UDP data exchange only. Shall I call anything periodically other than 
etharp_tmr() ?

Could somebody show me a trivial working sample code for UDP-only lwip driver 
(raw api, raw machine: no OS).
For example I'm a bit confused about netif_add() use: 
- netif_add() method has an argument "input"
- I guessed I sould put there pointer to my implementation of ethernetif_input()
- but there inside ethernetif_input() sample is a call "netif->input(p, netif)" 
-- infinite loop.

Thank you for your help/time.