Re: Raspberry Debug Probe query

Single Stage to Orbit <alex.buell@munted.eu> wrote:

Does anyone knows how to use the Raspberry Debug Probe with a Raspberry
Pi 3B? I've googled but the articles I've found only explains how to
use it with Raspberry Picos. I have a tricky issue to diagnose and it
needs hardware level debugging to see what's going wrong with it.

What do you want to debug?  The regular Pis have JTAG to which you can hook
up a debug probe and run something like OpenOCD+gdb on another machine (you
can likely do that from another Pi using GPIO, or a USB JTAG widget).  But
you're debugging the whole OS including all the daemons and whatnot that are
running on it.  Unless your issue is with the kernel itself (eg a boot
failure) or with some code running bare-metal, I don't think JTAG is going
to help much.

The Pico's Debug Probe provides SWD, which is for microcontrollers but not
for application-cores on the big Pis.  It provides 2 signal wires where JTAG
needs 4, so I don't think you could repurpose it for JTAG even if you wanted
to.

Theo