Check the open source licenses used in DJI Phantom 3 firmware, if any. In Order to do this, it is necessary to get a better insight into the structure of DJI Phantom firmware files.
This shows that Linux and other GPL code is used in the Phantom firmware. Hence, parts of the Phantom firmware would have to be provided by DJI in source form, however I could not locate the source code downloads on the DJI site. This project is to check the Phantom firmware for any open source code that might have such requirements.
The .bin files provided by DJI for firmware update are in fact firmware packages files. These packages consist of file header informations, a seek table and a varying number of firmware code modules.
A detailed analysis of the firmware package file structure can be found here firmware_package_structure.md
- Structure of package file header and seek table have to be found.
- Firmware code modules have to be extracted separately.
- Compressed code modules have to be unpacked.
- Each code module has to be checked for fingerprints of open source licensed code.
- DJI can than be asked to disclose specific parts of the code, which take advantage of open source licensed material.
See findings.txt for a dump of strings found in relevant parts of the firmware. This shows that Linux and other GPL code is used in the Phantom firmware.
As we can see below, the firmware contains references to Ambarella. According to this article, the Ambarella CEO noted that DJI "brought to market its Phantom 3 drones, both powered by Ambarella's A9 camera systems-on-chip". This fits to the fact that strings like autobuild_A9_Ambalink_AR6004/ambalink_sdk/host/usr/arm-buildroot-linux-gnueabi are found in the Phantom 3 Advanced firmware. According to the Product Brief, the Ambarella A9 has two ARM® CORTEX-A9 and one ARM® 11 cores and can do 4K.
As we can also see below, the firmware contains references to ThreadX, a proprietary Real Time Operating System (RTOS). Most interestingly, a dissection of the firmware shows many signs of Linux and Linux kernel drivers, which suggests that GPL code is most likely included in the Phantom 3 firmware.
binwalk ./P3X_FW_V01.02.0006.bin 2>&1 | grep Copyright
5592148 0x555454 Copyright string: " (c) 1996-2008 Express Logic Inc. * ThreadX ARM9/RVDS Version Gc. * ThreadX ARM9/RVDS Version G5.1.5.1 SN: 2923-115-1301 *"
35652448 0x2200360 Copyright string: " 2004-2014 Ambarella Corp.(PrSsg)"
43301892 0x294BC04 Copyright string: " (c) 1996-2014 Express Logic Inc. * ThreadX Cortex-A9/IAR Versic. * ThreadX Cortex-A9/IAR Version G5.6.5.1 SN: 3675-264-0901 *"
66914371 0x3FD0843 Copyright string: " (C) 2012 Free Software Foundation, Inc.ion, Inc."
66933671 0x3FD53A7 Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
66934126 0x3FD556E Copyright string: " (C) 2009-2012 Free Software Foundation, Inc.undation, Inc."
66934539 0x3FD570B Copyright string: " (C) 2009-2012 Free Software Foundation, Inc.undation, Inc."
66935000 0x3FD58D8 Copyright string: " (C) 2009-2012 Free Software Foundation, Inc.undation, Inc."
66935454 0x3FD5A9E Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
66936775 0x3FD5FC7 Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
66940059 0x3FD6C9B Copyright string: " (C) 2009-2012 Free Software Foundation, Inc.undation, Inc."
66988409 0x3FE2979 Copyright string: " (C) 2005-2012 by Zack T Smith."
67389568 0x4044880 Copyright string: " 1991, 1992, 1994, 1998, 1999, 2002 William D. Norcott2002 William D. Norcott"
69442897 0x4239D51 Copyright string: " (c) 2004-2014, Jouni Malinen <j@w1.fi> and contributorsj@w1.fi> and contributors"
72243006 0x44E573E Copyright string: " (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>ion, Inc. <http://fsf.org/>"
72246767 0x44E65EF Copyright string: "" also means copyright-like laws that apply to other kinds ofs that apply to other kinds of"
72377128 0x4506328 Copyright string: " (C) 2012 Free Software Foundation, Inc.ion, Inc."
72405405 0x450D19D Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
72406981 0x450D7C5 Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
72407475 0x450D9B3 Copyright string: " (C) 2007-2012 Free Software Foundation, Inc.undation, Inc."
72408139 0x450DC4B Copyright string: " (C) 2011-2012 Free Software Foundation, Inc.undation, Inc."
72408870 0x450DF26 Copyright string: " (C) 2008-2012 Free Software Foundation, Inc.undation, Inc."
72409379 0x450E123 Copyright string: " (C) 2008-2009, 2011-2012 Free Software Foundation, Inc.Software Foundation, Inc."
72409827 0x450E2E3 Copyright string: " (C) 2010-2012 Free Software Foundation, Inc.undation, Inc."
72684088 0x4551238 Copyright string: " (C) 2001-2012 Charles Cazabon."
72708984 0x4557378 Copyright string: " (C) 2012, Thomas G. Lane, Guido Vollbedingo Vollbeding"
73801163 0x4661DCB Copyright string: " (c) 2003-2014, Jouni Malinen <j@w1.fi> and contributorsj@w1.fi> and contributors"
74606570 0x47267EA Copyright string: " (c) 2002-2014, Jouni Malinen <j@w1.fi> and contributorsj@w1.fi> and contributors"
75176721 0x47B1B11 Copyright string: " (C) 2001-2011 Alvaro Lopez Ortega.ega."
75251692 0x47C3FEC Copyright string: " (C) 2001 - 2011 <a href="http://www.alobbs.com/">Alvaro Lopez //www.alobbs.com/">Alvaro Lopez Ortega</a> <alvaro@alobbs.co"
75684779 0x482DBAB Copyright string: " (c) 2000-2013 Simon KelleyyZDNLERKzowefnbvhdkqr:m:p:c:l:s:i:t:u:g:a:x:S:C:A:T:H:Q:I:B:F:G"
75746809 0x483CDF9 Copyright string: " (c) 2004-2014, Jouni Malinen <j@w1.fi> and contributorsj@w1.fi> and contributors"
76557967 0x4902E8F Copyright string: " (C) 2013, Ambarella Inc."
78667783 0x4B06007 Copyright string: " (C) 2003-2010 Thomas Graf <tgraf@redhat.com>af@redhat.com>"
79068167 0x4B67C07 Copyright string: " 1995-2013 Jean-loup Gailly and Mark Adler Mark Adler "
79268580 0x4B98AE4 Copyright string: " (C) 2012, Thomas G. Lane, Guido Vollbedingo Vollbeding"
85660269 0x51B126D Copyright string: " (C) 2006 Free Software Foundation, Inc.ion, Inc."
89394065 0x5540B91 Copyright string: " (C) 2012 Free Software Foundation, Inc.ion, Inc."
89516078 0x555E82E Copyright string: " (c) 2002 The OpenTSA Project. All rights reserved. All rights reserved."
89540571 0x55647DB Copyright string: " (C) 2001 Erik Andersen <andersen@codepoet.org>en@codepoet.org>"
92590284 0x584D0CC Copyright string: " (c) 1996-2014 Express Logic Inc. * ThreadX Cortex-A9/IAR Versic. * ThreadX Cortex-A9/IAR Version G5.6.5.1 SN: 3675-264-0901 *"