White Rabbit console
FECs which include a White Rabbit core provide a console to control and debug that core. The SPECv4 card has a USB port near the back of the card and the SCU has a UART connector on the front, see the photos below.
The console is 115200 8N1 with no flow control (neither HW nor SW). Try "minicom -D /dev/ttyUSB0". If that does not work try "USB1" instead of "USB0" or try as "sudo".
The commands supported by the console are documented in the White Rabbit PTP Core Manual (ignore the build instructions and skip to Appendix A).
Especially useful commands are: "gui", "mac", and "ip".