Starting of an outline of how I dumped the firmware off of an Actiontec device through the UART interface. More to expand on.

1. Get a friend with a steady soldering hand to put on some header pins after using the flashlight trick to figure out the GRND pin.

2. Connect USB->UART interface (Used an FTDI based device, no drivers required).

3. Serial program minicom, start logging, send a break to break the countdown and drop into the CFE> interface.

4. dm to dump to a log file.

5. Edit log file to make sure only hexdump with address is there.

6. Use xxd -r to transform hexdump file into binary file.

7. Use binwalk on file to extract the images. Document weird headers here.

Reference: Dumping Firmware