GoodFET Tutorials

Construction

Construct your GoodFET using the components listed in its Hardware page. As of March 2010, you probably want a GoodFET3x for embedded systems development or a GoodFET2x for voltage glitching security research. All previous models are still supported by the programming software.

If you are new to surface mount components, start with the Construction Guide.

Verification

If your GoodFET is properly assembled, you should see a notice in dmesg that an FTDI USB/Serial adapter has been added on insertion of the device. The device name varies with operating system, but it's probably one of /dev/ttyUSB0, /dev/ttyU0, or /dev/tty/cu.usbserial-*.

You should also see the RX/TX LEDs blink briefly when inserting the device. If they do not, their polarity is likely wrong and you will need to desolder and rotate them. For those without an SMD rework station, it might be easier to burn the LEDs off and apply fresh ones.

Software

Until a stable release of the GoodFET software is available, you will need to track the project by svn. This makes upgrading a breeze, but you will not be able to install the software by your favorite Linux distribution's package manager.

Running the following commands will download the latest version of the project to ~/svn/goodfet and link the client scripts into /usr/local/bin/. Optionally, you may add the client directory to your $PATH if you do not have sudo privileges.

mkdir ~/svn
cd ~/svn
git clone https://github.com/travisgoodspeed/goodfet goodfet
cd goodfet/trunk/client
sudo make link

The client requires a number of prerequisite packages, most notable python-sqlite3 and python-serial. For Windows, you need a 32-bit version of Python as python-serial does not work in 64-bit on that platform.

You will also need to set an environment variable so that the GoodFET client knows which model of GoodFET you have. For example, if you have a GoodFET41, set the variable like so in your /etc/environment script.

export board=goodfet41

Now that the software is installed, dump the info flash of your GoodFET to a text file for safekeeping. This information is destroyed when flashing the device, and in the rare even that it is needed, it is very handy to have. If you have the time, it would be nice to email a copy of this file to Travis Goodspeed <travis at radiantmachines.com>.

goodfet.bsl --dumpinfo >info.txt

Once this backup has been made, you can use goodfet.bsl to install a recent version of the firmware from the Internet. This is faster than building the firmware from scratch, which is described in the next section.

goodfet.bsl --fromweb
goodfet.monitor test

Firmware

There are two ways to get the firmware. By far the fastest is to use the web version by 'goodfet.bsl --fromweb', but participation in development of the project will require you to build it from scratch.

The mspgcc compiler is preferred for the project. Binary packages used to be hard to find, but nowadays you can just install it from many unix package repositories. In Ubuntu (11.10 or later with universe enabled) or Debian, use the following.

pro% apt-cache search msp430
binutils-msp430 - Binary utilities supporting TI's MSP430 targets
gcc-msp430 - GNU C compiler (cross compiler for MSP430)
gdb-msp430 - The GNU debugger for MSP430
msp430-libc - Standard C library for TI MSP430 development
msp430mcu - Spec files, headers and linker scripts for TI's MSP430 targets
mspdebug - debugging tool for MSP430 microcontrollers
pro% sudo apt-get install binutils-msp430 gcc-msp430 msp430-libc msp430mcu

Once you have a working compiler and client, you can compile and install the firmware like so. Be sure that your $board variable is set as described earlier in the tutorial.

pro% cd ~/svn/goodfet/trunk/firmware 
pro% board=goodfet41 make clean install

You probably also want to install the info file, as this saves your GoodFET from having to autocalibrate its clock. With info.txt in your firmware directory, run the following.

pro% cd ~/svn/goodfet/trunk/firmware 
pro% board=goodfet41 make installinfo

Use

Once your GoodFET has been flashed with the appropriate firmware and an info file, you can grab a list of installed applications from the monitor.

pro% board=z1 goodfet.monitor listapps full
GoodFET with f26f MCU
Clocked at 0x8f74
Build Date: 2012-03-27 17:11
Firmware apps:
Monitor
        The monitor app handles basic operations on the MSP430
        such as peeking and poking memory, calling functions and
        managing the baud rate.

SPI
        The SPI app handles the SPI bus protocol, turning
        your GoodFET into a USB-to-SPI adapter.

CCSPI
        The CCSPI app adds support for the Chipcon SPI register
        interface. Unfortunately, there is very little similarity
        between the CC2420 and the CC2500, to name just two of the
        myriad of Chipcon SPI radios.  Auto-detection will be a bit
        difficult, but more to the point, all high level functionality
        must be moved into the client.

pro%

For more usage information, see the list of Clients on the left. Wiring diagrams can be found in the list of Firmware Applications.