I have an issue that I need a second opinion on. I finally got my udoo quad up and running and plan on using it as a router/firewall. I purchased a POE adapter off of amazon and plugged it into my udoo. It seems to work great - I can power the udoo without the AC adapter. The problem I'm running into is that it appears that Debian/Linux doesn't either have a driver for it or it's not detecting it properly as I can't assign an IP address to it or the interface itself does not seem to be detected in the OS. I did remove all the GUI components...so perhaps I removed something I shouldn't have... I also tried to plugin a USB ethernet adapter and that doesn't seem to be working either. Here is my dmesg output - http://paste.debian.net/104383/ As you can see it doesn't seem to pick up the USB or POE modules.
The network interface part of that Ethernet shield you have is not compatible without modification, and not suitable for router/firewall use even if you did get it to work. It's meant to support simple network communication (like data logging) from the small Arduino's that don't run any OS and lack anynative IP support-- so the chip on that shield handles most network protocol tasks itself, sending and receiving from its host only payload data via SPI synchronous serial. Notice that 6-pin header on the bottom of the board? It is designed to mate with the SPI/ICSP header on an Arduino, which doesn't exist there on Udoo since one of the CPU chips has taken its spot. There is an equivalent 4-pin SPI header near the USB ports, which you could solder a pigtail onto the Ethernet shield to mate with, but even then the shield would only be accessible to the Arduino/SAM3X side, not to Linux/i.MX6. Well, the i.MX6 has SPI interfaces available too, so technically you could wire up the shield's W5100 to these, but no Linux device driver exists so one would have to be written from scratch. And SPI being a slow bus, typically running at 2Mb/s or less, would severely bottleneck any routing application. The USB NIC can probably be made to work, though, after recompiling the kernel to add necessary driver support. Check the output of "lsusb" to see what type yours is. This will indicate which driver it needs.
