Remember the location of this binary on your RPi2, we’ll need it later. This binary simply changes the GPIOs to ALT functions (i.e, routes these specific GPIO pins to an alternative function, which in this case is routed to the ARM JTAG pins.)

sudo ./JtagEnabler

Next we’ll fire up OpenOCD and attempt to connect! (You may need to use a different configuration file for your interface depending on which device you are using. FTDI devices are cheap and work very well) Since I have the TUMPA, I am using the TUMPA configuration file in the FTDI devices folder.

sudo openocd -f interface/ftdi/tumpa.cfg -f rpi2.cfg

If all goes well, we should see the four cores halt, and we’re ready to debug. If you have any questions or comments, please post in the comment section below! Thanks for reading.

(Note: I’m hoping to put together a SWD tutorial soon, so c’mon back in the near future.)