Author: Uwe Hermann

I'm happy to finally announce an open-source (GNU GPL), cross-platform (Linux, Mac OS X, FreeBSD, Windows, ...) logic analyzer software package myself and Bert Vermeulen have been working on for quite a long time now: sigrok (it groks your signals).

History

I originally started working on an open-source logic analyzer software named "flosslogic" in 2010, because I grew tired of almost all devices having a proprietary and Windows-only software, often with limited features, limited input/output file formats, limited usability, limited protocol decoder support, and so on. Thus, the goal was to write a portable, GPL'd, software that can talk to many different logic analyzers via modules/plugins, supports many input/output formats, and many different protocol decoders.

The advantage being, that every time we add a new driver for another logic analyzer it automatically supports all the input/output formats we already have, you can use all the protocol decoders we already wrote, etc. It also works the other way around: If someone writes a new protocol decoder or file format driver, it can automatically be used with any of the supported logic analyzers out of the box.

Turns out Bert Vermeulen had been working on a similar software for a while too (due to exactly the same reasons, crappy Windows software, etc.) so it was only logical that we joined forces and worked on this together. We kept Bert's name for the software package ("sigrok"), set up a SourceForge project, mailing lists, IRC channel, wiki, etc. and started working.

Overview, Features

You can get the lastest sigrok source code from our main git repository:

  $ git clone git://sigrok.git.sourceforge.net/gitroot/sigrok/sigrok

Here's a short overview of sigrok and its features as of today. The software consists of the following components:

• libsigrok, a shared library written in C, which contains the general infrastructure for handling logic analyzer data in a streaming fashion.
  
  It also contains the individual hardware drivers which add support for various logic analyzers. Currently supported hardware includes: Saleae Logic, CWAV USBee SX, Openbench Logic Sniffer (OLS), ZEROPLUS Logic Cube LAP-C, ASIX Sigma/Sigma2, ChronoVu LA8, and others. Many more devices are on our TODO list (and we already own them), it's just a matter of time to reverse engineer the USB protocols and implement a driver for them.

  Thanks ASIX for being open and helping with the ASIX Sigma driver, and many thanks to ChronoVu for being open as well and providing information about the ChronoVu LA8 protocol! Thanks to Håvard Espeland, Martin Stensgård, and Carl Henrik Lunde (who contributed the ASIX Sigma driver), Sven Peter and "Haxx Enterprises"/bushing (for contributing the ZEROPLUS Logic Cube LAP-C driver, ported from their zerominus tool). Also, thanks to Daniel Ribeiro and Renato Caldas who worked on the Link Instruments MSO-19 driver (still work in progress).

  Finally, libsigrok also contains the individual input/output file format drivers. Currently supported are: sigrok session (the default format, which contains all metadata), bits, hex, ASCII, binary, gnuplot, the OpenBench Logic Sniffer format, the ChronoVu LA8 format, Value Change Dump (VCD) viewable in gtkwave, and Comma-separated values (CSV).
  

• libsigrokdecode, a shared library written in C, which contains the protocol decoder infrastructure and the protocol decoders themselves, which are written in Python (>= 3.0).

  The list of currently supported protocol decoders includes:
  

    dcf77                DCF77 time protocol
    lpc                  Low-Pin-Count
    mx25lxx05d           Macronix MX25Lxx05D
    jtag_stm32           Joint Test Action Group / ST STM32
    i2s                  Integrated Interchip Sound
    spi                  Serial Peripheral Interface
    edid                 Extended display identification data
    pan1321              Panasonic PAN1321
    mlx90614             Melexis MLX90614
    jtag                 Joint Test Action Group
    rtc8564              Epson RTC-8564 JE/NB
    transitioncounter    Pin transition counter
    usb                  Universal Serial Bus
    i2cdemux             I2C demultiplexer
    i2c                  Inter-Integrated Circuit
    i2cfilter            I2C filter
    mxc6225xu            MEMSIC MXC6225XU
    uart                 Universal Asynchronous Receiver/Transmitter
  

  Many more decoders are on our TODO list, and we especially welcome contributed protocol decoders, of course! We intentionally chose Python as implementation language for the decoders, to make them as easy to write (and understand) as possible, even if that means that performance suffers a bit. Have a look at the SPI decoder for example, to get a feeling for the implementation.

  Protocol decoders can be stacked on top of each other, e.g. you can run the i2c decoder and pipe its output into the rtc8564 (Epson RTC-8564 JE/NB) decoder for further processing of the RTC-specific, higher-level protocol. We also plan to support more complex stacking and combining of decoders in various ways in the nearer future.

• sigrok-cli, is a command-line frontend, which uses both libsigrok and libsigrokdecode. It can acquire samples from logic analyzers and output them in various formats into files or to stdout, and/or run protocol decoders on the aquired data.

  Example: Data acquisition with 1MHz samplerate into a file.
  

   $ sigrok-cli -d chronovu-la8:samplerate=1mhz --time 1ms -o test.sr
  

  Example: Protocol decoding (JTAG).
  

   $ sigrok-cli -i test.sr -a jtag:tdi=5:tms=2:tck=3:tdo=7
   [...]
   jtag: "New state: EXIT1-IR"
   jtag: "IR TDI: 11111110, 8 bits"
   jtag: "IR TDO: 11110001, 8 bits"
   jtag: "New state: UPDATE-IR"
   jtag: "New state: RUN-TEST/IDLE"
   [...]
  

• sigrok-qt, a Qt-based GUI for sigrok, using both libsigrok and libsigrokdecode.

  This is intended to be a cross-platform GUI (runs fine and looks "native" on Linux, Windows, Mac OS X) supporting data acquisition and protocol decoding.

  NOTE: The Qt GUI is not yet usable! We're working on getting it out of alpha-stage for the next release.

• sigrok-gtk, a GTK+-based GUI for sigrok, using both libsigrok and libsigrokdecode (soon).
  
  This is a cross-platform GUI contributed by Gareth McMullin (thanks!), supporting data aqcuisition (and soon protocol decoding).

  NOTE: The GTK+ GUI is not yet fully usable (but it's more usable than sigrok-qt)! Consider it alpha-stage software for now.

We're happy to hear about other (maybe special-purpose) frontends you may want to write using libsigrok/libsigrokdecode as helper libs!

Firmware

Some logic analyzer devices require firmware to be uploaded before they can be used. As always, firmware is a bit of a pain, but here's what we currently do: For non-free firmware we provide instructions how to extract it from the vendor software or from USB dumps, if possible. For distributable firmware we have a git repo where you can get it (thanks ASIX for allowing us to distribute the ASIX Sigma/Sigma2 firmware files!).

  $ git clone git://sigrok.git.sourceforge.net/gitroot/sigrok/sigrok-firmwares

Finally, for all Cypress FX2 based logic analyzers we have an open-source (GNU GPL) firmware named fx2lafw, started by myself, but most work (and finishing the firmware) was then done by Joel Holdsworth, thanks! The support list includes Saleae Logic, CWAV USBee SX, CWAV USBee AX, Robomotic Minilogic/BugLogic3, Braintechnology USB-LPS, and many others. Get the code from the fw2lafw git repository:

  $ git clone git://sigrok.git.sourceforge.net/gitroot/sigrok/fx2lafw

Example dumps

We collect various captured logic analyzer signals / protocol dumps in the sigrok-dumps git repository:

  $ git clone git://sigrok.git.sourceforge.net/gitroot/sigrok/sigrok-dumps

They can be useful for testing the sigrok command-line application, the sigrok GUIs, or the protocol decoders.

We're happy to include further contributed example data in our repository, please send us .sr files of any interesting data/protocol you may come across (even if sigrok doesn't yet have a protocol decoder for that protocol). See the Example dumps wiki page for details.

Packages, distros, installers

I'm currently working on updated Debian packages for sigrok (will be apt-get install sigrok to get everything), and we're happy about further packaging efforts for other distros. We have preliminary Windows installer files (using NSIS), but the Windows code needs some more fixes and portability improvements before it's really usable. On Mac OS X you can use fink/Macports to install as usual, fancier .app installer files are being worked on.

Future

Apart from support for more logic analyzers, input/output formats, and protocol decoders, we have a number of other plans for the next few releases. This includes support for analog data, i.e. support for (USB) oscilloscopes, multimeters, spectrum analyzers, and such stuff. This will also require additional GUI support (which could take a while). Also, we want to improve/fix the Windows support, and test/port sigrok to other architectures we come across. Performance improvements for the protocol decoding as well as more features there are also planned.

Contact

Feel free to contact us on the sigrok-devel mailing list, or in the IRC channel #sigrok on Freenode. There's also an identi.ca group for sigrok. We're always happy about feedback, bug reports, suggestions for improving sigrok, and patches of course!

Only few days ago a long-standing bug in coreboot, the Free Software x86 BIOS/fimware project, has been fixed: Adding support for a laptop/notebook.

The code was developed by coresystems GmbH (thanks a lot!). Quoting from the announcement:

coreboot® is running on a multitude of different computers, ranging from tiny embedded systems as small as the palm of your hand over desktop and server systems to super computers with thousands of nodes. However, one might say that in the area of mobile computers coreboot has to catch up, compared to its support of other devices.

Thus, I am especially glad to announce that ">coresystems GmbH is releasing coreboot® for the Roda RK886EX a.k.a Rocky III+ notebook today. It's a rugged notebook, protected against shock, vibration, dust and humidity:
http://www.roda-computer.com/en/products/notebooks/rocky-iii-rk886ex.html

We have been testing various Linux distributions as well as Windows XP and Windows 7 booting on this nice notebook.

I want to sincerely thank those who made this project possible with their funding:

• secunet Security Networks AG
• Bundesamt für Sicherheit in der Informationstechnologie (Federal Office for Information Security, BSI)

A big thank you also goes to everyone who worked with coresystems on this project.

The committed patch series includes improved support for the Intel i945 / ICH7 chipset (which was also written by coresystems), the SMSC LPC47N227 Super I/O, the Texas Instruments Cardbus+Firewire bridge TI PCI7420, and finally the Renesas M3885x Embedded Controller (EC).

Btw, the latter, the so-called embedded controller (sometimes integrated in the Super I/O, sometimes it's an extra chip) is one of the major problems for coreboot support on laptops. They are almost always undocumented (i.e., no public datasheets are available), but they have low-level control over power/battery management, early power-up sequence, and often include keyboard controller functionality and other important stuff. Luckily, for this notebook an EC datasheet is available. Checkout the coreboot EC support code for the Renesas M3885x for an impression of what this stuff is all about.

Anyway, there is hope that this laptop will only be the first in a row of multiple supported ones in the future. Interested developers and contributors are of course always welcome on the coreboot mailing list :-)

Nice coreboot news — the Free Software x86 firmware ("BIOS") is featured on the cover of issue 186 of the Linux Journal.

Anton Borisov's article Coreboot at Your Service! explains the basic ideas behind coreboot, how to build an image for your board, which payloads are available and how they are used, e.g. GRUB2, SeaBIOS if you need legacy BIOS callbacks (e.g. for booting Windows), Etherboot/GPXE, or more fun stuff such as space invaders or tint (a tetris clone) in your flash ROM chip...

If you read the article and think the build process is a bit complicated and ugly, do not despair! We're currently in the process of converting the whole coreboot code base to use kconfig (the widely-known configuration tool used by the Linux kernel, busybox, and other projects), so in the very near future the whole process for building a coreboot image will work like this:

  $ make menuconfig
  $ make

Flashing the image can then be done using an EEPROM programmer and/or via the user-space utility flashrom (available for Linux, Mac OS X, FreeBSD, etc.)...

It's nice to see that coreboot is getting more and more coverage in "mainstream" media and is growing both in number of deployments and in number of supported chipsets and boards.

We are desperately in need of more developers though, there are just way too many chipsets, boards, and datasheets out there; we're happy about every patch and every new tester or developer who likes to mess with code that runs in the very first few (micro)seconds after power-on.

If you think kernel hacking and related low-level development is nice, you might also be interested in writing code where there's no RAM yet (as coreboot has to initialize it), there's no serial port for debugging (coreboot has to initialize it), no PCI devices have been set up, most of your auxiliary hardware is not yet up (ethernet NIC, parallel port, audio, IDE, SATA, USB, you name it). It's a fun environment to work in and you'll learn a lot about PC hardware, even if you (so far) thought you knew everything there is to know.

Feel free to join us on the mailing list or on IRC in #coreboot on Freenode.