[lwip-users] Xilinx lwIP raw-api beginner question

[Erik Jagre]

Hi, I am a lwIP beginner and have some questions about getting a raw-api
application up and running on a Xilinx Spartan-3E 1600E MicroBlaze
Development Kit.

I have tried to run the xilinx reference design xapp663 (echo server)
but without success. It seems like my design never takes care of
incoming traffic. When I try to connect to my echo-server with telnet
ARP requests are sent to the development board. But my design never
replies.

I have tried to use the lwip-debug feature, but my program gets stuck
during the call to netif_add (this does not happen without the
lwip-debug feature activated). A print-out is made that confirms that
the IP address has been set but after that the program stops and the
program counter is set to 0x00. This makes me belive that my call to
netif_add is not done in the right way. How is netif_add used correctly?
What preparations need to be done before calling it?

I am also curious about how xemacif_input(default_netif) works. Is this
the call that takes care of all incoming traffic? Or is another call
needed to take care of ARP requests?

My code is included in the zip-file.

Grateful for any suggestions or ideas.

Regards 
Erik

echo.zip
Description: echo.zip