The PB board that I have does not match up with the JP connector pinouts in the FAQ section -- rather, it's the board that's photographed in the same thread.
I have:
JP1: 2-pin jumper, with a jumper on it, next to a single pin that's labelled "156" (maybe that's 7312 pin 156, ie reset, and this is the internal boot rom enable jumper?
JP2: 2-pin jumper, no jumper present
JP3: 2x7 pads (no connector)
JP4: same footprint as JP3, but with a 2x7 header socket.
I don't have a JP5-JP9.
Hopefully, someone can tell me which of these corresponds to at least the ARM JTAG, and maybe the ARM UART1?
*bangs head against wall*
Ben