I am working with a development board from Altera. My boss built a small "virtual" Ethernet-MAC device into the Stratix II FPGA within the Nios II processor system. This MAC is not connected to a Physical but only takes a packet in its FIFO and sends it out again right afterwards. I programmed a device driver that is intended to work with this "virtual" MAC. The structure of the driver is taken from the lan91c111 from SMSC that came with the development kit. And I also programmed a small Application Programm "web_server" that sends a packet to the lwIP TCP/IP Stack and tries to receive it again right afterwards. During project bulid of the web_server application the driver for the "virtual" MAC is compiled successfully and the "virtual" MAC is listed in the system.h file of the System Library of the web_server Application. http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/huh.gif The problem is: a: The driver is not being registered int the alt_sys_init.c file of the System Library of the web_server Application. b: When lwip_devices_init(...) in the web_server is called, the driver for the "virtual" MAC is not being initialised because there is no entry for it in the alt_lwip_device_list. Does anyone have an idea what I might be doing wrong? I would be very happy about any answer!