November 11, 2017

JTAG and remote GDB on the Beaglebone Black

I have been using OpenOCD along with GDB on some ARM Cortex-M3 projects and started wondering what could be arranged along these lines with the BBB. This is just "recon" information, I have not actually followed through with any of this.

Note that the original Beaglebone (the Beaglebone White) offers JTAG via FTDI serial over USB in some way. It also has the pads for the 20 pin connector on the bottom of the PCB. One has to suspect that JTAG via serial would be pretty slow, but who knows.

JTAG

The BBB has full blown JTAG connections in the form of solder pads on the bottom of the board. So if you want hardware JTAG, you can get it with some careful soldering. You need a 20 pin connector (in 2 rows of 10), and what you need is a Samtech FTR-110-03-G-D-06. Some sources give the part number as Samtech FTR-110-03-G-06. I ordered the longer number with the "D", which indicates a dual row of pins. I think it is the same thing and they just enhanced their part number scheme, but we will see.

The Flyswatter2 is a $89 item. Note that this is considered an inexpensive JTAG tool. The cable and adapter to attach it to the BBB is another $39, so you are talking $128 to get set up to do JTAG with your BBB. With this, you run OpenOCD, GDB, and go to town. A painful comparison with buying an STLINK V2 for $5 to do the same thing with an ARM Cortex-M3.

The last 2 links above discuss using the BBB itself as a bus-pirate like tool. The reverse of what I am interested in doing just now, but interesting for future reference.

GDB

The following articles discuss user space GDB using the remote protocol.

Feedback? Questions? Drop me a line!

Tom's Computer Info / [email protected]