JTAG? Really? I Have JTAG?

Karim's slide 13 says that the Beaglebone has "Single-cable USB/Serial/JTAG."

I've seen the USB cable supply power and serial, but JTAG? Hmm. I really know nothing about JTAG, but I think of it as a low-level, run-time, debugging tool that requires a special connector,  special tools on the host end, and a EE degree to use it.

A quick google for "JTAG beaglebone" lands me here.

Yes, it really does let me do JTAG! Looks like TI has a free tool, Code Composer Studio, that's an Eclipse plugin to do JTAG stuff. On the Beaglebone, it can do all the relevant work over the power/serial cable. Whatever that work may be.

There's lots of stuff here to explore, eventually.