May 3, 2014
What Anderson envisages -- more of the same but with greater diversity and
competition -- may come to pass. But to set the threshold for the third
industrial revolution so low just because someone somewhere forgot to
regulate A.T. & T. (or Google) seems rather unambitious.
- Evgeny Morozov, "Making It", The New Yorker, Jan 13 2014
At the time of this writing, 3D Robotics distributes the open source APM Mission Planner with a restriction that prevents uploading firmware open-hardware Pixhawk boards which were not manufactured by 3D Robotics.
This is an alternative bootloader for non-3DR Pixhawk boards that bypasses the restriction built into the Mission Planner. Any Pixhawk board with this bootloader will report the serial number and COA (Certificate of Authenticity) data given by an authentic 3DR Pixhawk board.
The restriction in the APM Mission Planner binary restricts user freedom to interoperate between open source hardware and open source software. In my opinion, this restriction is contrary to the spirit of open source.
The authentication features implemented in the APM Mission Planner do not violate the open source license of that software. However almost all APM Mission Planner users expect to use the software by downloading the official binary (distributed on ardupilot.com, a website owned by 3D Robotics). This official version, upon detecting a non-authentic 3DR Pixhawk, will refuse to upload firmware to the Pixhawk.
The Mission Planner is open source software, and the authenticity check may be bypassed by changing a single line of the source code. Under the software license, others are free to distribute binaries and source for the Mission Planner with this modification. However, this forces users to either compile their own Mission Planner, which is a complex technical operation out of scope for most users, or to trust that a binary version provided by a third party contains only the required modification and not any extra malicious code.
This bootloader sidesteps the restrictions of the official Mission Planner binary. I do not believe Mission Planner users should be required to build their own binaries, or trust binaries from an untrustworthy third party, in order to have freedoms within the spirit of open hardware and open source software. You are welcome to disagree with my beliefs or my own definition of "the spirit of open source".
3D Robotics has supported the APM, Pixhawk, and APM Mission Planner open source projects with both direct financial support of project maintainers, and provided free prototype and production hardware to many of the development team members. 3DR's support of the developers has been beneficial to the quality of software and hardware provided by these projects. At this time and to the best of my knowledge, no other manufacturers of Pixhawk hardware has provided support, directly or indirectly, to the maintainers or contributors of any of these open source projects.
While 3D Robotics has done an enormous amount to support the developer team, that support has thus far not come with any "strings attached". Open source contributors paid or otherwise supported by 3DR retain copyright of their work, and all of that work is available under the open source license of the parent project (GPL, BSD, or CC-BY-SA, where applicable).
This is the first time I've seen 3D Robotics use their support of a open source contributors to impose restrictions on competing hardware manufacturers. While the Mission Planner project maintainers have every right to follow 3DR's direction to include this restriction, 3DR's directions are bad stewardship of the open source community, because they reduce user freedoms for their own gain. This precedent reduces the legitimacy of the entire family of 3DR supported open source projects, and ought to make contributors and competitors alike less comfortable supporting these projects. To restore community trust, 3DR should remove the authenticity restrictions from the Mission Planner.
You will need to build it and reflash the Pixhawk bootloader using a JTAG debugger. If you don't already know exactly what that means, the upgrade isn't for you - it entails having the correct toolchain on your computer, having access to a JTAG debugger and either using a solderless connection jig or soldering a surface mount JTAG pin header to the Pixhawk board.
This bootloader may be flashed at the factory by a non-3DR Pixhawk manufacturer, as an alternative to flashing the standard Pixhawk bootloader. Users of a board with this bootloader will not need to use an unofficial distribution of the APM Mission Planner for firmware upgrade.
This is a fork of the PX4 open source project bootloader. I want to emphasize that the official bootloader, nor any of the PX4 project's firmware upload software, uses the board authentication features to restrict use of any hardware or software.
Lorenz, the PX4 project lead, pointed out that the project name may reflect poorly on their project. This was not my intention, and I regret any confusion this causes.
The official bootloader reports the values true values of the serial number and one-time programmable (OTP) memory on the STM32F4 chip. This bootloader lies when reporting those fields, instead reporting values from a 3DR-manufactured Pixhawk board purchased by the author.
I'm Pat Hickey, a software developer from Portland, Oregon. In the past I served as one of the maintainers of the ArduPilot (APM) open source project. I became involved in the APM project in mid 2011, and my last commit to the APM project was in Feburary 2013.
During that time, my major contributions were adding hardware support for the APM2 board, and the AP_HAL Hardware Abstraction Layer which permitted hardware support of non-Arduino based boards, which included PX4 project hardware, the second generation of which is the Pixhawk.
I have collaborated with 3DR on many of hardware and software projects in the past. I've considered all of those collaborations to be positive and do not wish 3DR badly. I have never received direct financial support from 3DR, but they have sent me a bunch of free hardware and paid my travel expenses to speak at DroneCon in 2013.
Currently, I'm the engineering lead of the SMACCMPilot Project, a research project building high assurance open-source autopilot software. SMACCMPilot uses open source software derived from the APM open source project and the PX4 project. It is research software and not intended to provide a user alternative to the APM project software at this time.
lol, no. All opinions on this page are my own. Please send all hate mail to
pat@moreproductive.org.