Bus Pirate: OpenOCD

Summary

Open On-Chip Debugger (OpenOCD) software was created by Dominic Rath at the University of Applied Sciences Augsburg. The goal of this software is to provide debugging tools for a lot of different debugging adapters and platforms. It has a scripting language that allows creating configuration files for e.g. custom JTAG adapters or target platform.

This tutorial is an updated version to [1]

Requirements

• OS: Linux

In order to complete these steps, you must have followed Bus Pirate: First steps before.

In order to use OpenOCD on the Bus Pirate you need a firmware version of 6+

Installation

Download OpenOCD

git clone https://github.com/arduino/OpenOCD.git

Install dependencies for the OpenOCD build:

sudo apt-get install autotools-dev

sudo apt-get install automake

Compile code

cd OpenOCD

./bootsrap

./configure --enable-maintainer-mode --disable-werror --enable-buspirate

make

sudo make install

Configure OpenOCD's buspirate.cfg

nano tcl/interface/buspirate.cfg

#
# Buspirate with OpenOCD support
#
# http://dangerousprototypes.com/bus-pirate-manual/
#
interface buspirate
# you need to specify port on which BP lives
buspirate_port /dev/ttyUSB0                     (select the correct PORT!!!)
# communication speed setting
buspirate_speed normal ;# or fast
# voltage regulator Enabled = 1 Disabled = 0
buspirate_vreg 0
# pin mode normal or open-drain
buspirate_mode open-drain
# pullup state Enabled = 1 Disabled = 0
buspirate_pullup 1
# this depends on the cable, you are safe with this option
reset_config srst_only

Connect Bus Pirate and OpenOCD

Connect the Bus Pirate to the computer

Start OpenOCD

cd OpenOCD

sudo openocd -f tcl/interface/buspirate.cfg

(Errors might appear)

$ sudo openocd -f tcl/interface/buspirate.cfg              
Open On-Chip Debugger 0.10.0-rc1-dev-gc404ff5d-dirty (2019-11-11-15:43)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Warn : Adapter driver 'buspirate' did not declare which transports it allows; assuming legacy JTAG-only
Info : only one transport option; autoselect 'jtag'
srst_only separate srst_gates_jtag srst_open_drain connect_deassert_srst
Info : Buspirate Interface ready!
Info : This adapter doesn't support configurable speed
Warn : There are no enabled taps.  AUTO PROBING MIGHT NOT WORK!!
Error: JTAG scan chain interrogation failed: all ones
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Warn : Bypassing JTAG setup events due to errors
Warn : gdb services need one or more targets defined

Start OpenOCD session

Open a new terminal tab

type: telnet localhost 4444

The OpenOCD terminal should open

Type help for all possible operations

Used Hardware

Bus Pirate v3.6 Universal serial interface

References

• https://research.kudelskisecurity.com/2014/05/01/jtag-debugging-made-easy-with-bus-pirate-and-openocd/
• https://github.com/arduino/OpenOCD