dji-firmware-tools: Extracting and Modifying DJI Drone Firmware

What dji-firmware-tools Does and Who It Is For

DJI drones run firmware on multiple programmable chips. The main firmware package downloaded from DJI bundles these individual module binaries together. dji-firmware-tools provides Python scripts to unpack that bundle, extract individual modules, decrypt or un-sign them where keys are available, modify their content, and re-pack them into a flashable firmware package.

The project started as an alternative implementation of the parser from phantom-licensecheck and has expanded to cover many generations of DJI products. It supports hardware-independent analysis of firmware files and product communication tools that connect to a drone over serial (UART) or I2C interfaces.

The README states directly that the tools are for engineers with hardware and software knowledge, and warns that those who cannot understand how the tools work should not use them. This is not a general caution: the README explains that incorrect use can produce damaged firmware, and that warnings in the tool output must be investigated before proceeding. The project wiki contains detailed hardware and component information for boards within each drone, contributed by enthusiasts and repair technicians.

Key Use Cases from the README

The README describes five concrete use cases. The first is calibration after repair: when replacing components such as gimbals with Hall sensors, the tools can trigger calibration or factory functions like pairing by sending custom packets to the drone.

The second is parts identification. The project wiki documents boards and components at the chip level, which is useful for repair technicians who need to identify components before ordering replacements or deciding whether to open a drone.

The third is flight parameter modification. DJI Flight Controllers define hundreds of parameters that control behavior. These can be changed by sending a command to the drone, as long as the new value falls within the limits accepted by the firmware. This allows the tools to function as a command-line equivalent of DJI Assistant for platforms where the official software locks advanced functions.

The fourth is firmware modification at the binary level: disabling hardware pairing, extending parameter ranges, removing limits, enabling unused hardware features, and integrating additional devices. The README acknowledges that flashing modified firmware may require additional steps such as rooting, because some firmware packages are signed with asymmetric cryptography and private keys are rarely available.

The fifth is research: capturing and analyzing communication between drone modules, comparing firmware across product generations, extracting binaries, converting to ELF format for disassembly, parsing flight logs, and finding security vulnerabilities.

The Main Extraction and Decryption Tools

Two tools handle the core firmware unpacking workflow. The first, `dji_xv4_fwcon.py`, handles firmware packages that start with the `xV4` magic bytes. It extracts modules from the container or creates a container by merging modules. For a Phantom 3 Pro firmware package, the extraction command from the README is:

./dji_xv4_fwcon.py -vv -x -p P3X_FW_V01.08.0080.bin

The second, `dji_imah_fwsig.py`, handles modules in `.sig` files that start with `IM*H`. It decrypts and un-signs modules after they have been extracted. Keys for encryption and authentication have changed across product generations. When a file refers to a key for which multiple versions exist, the tool displays a warning and selects the most recent version. Un-signing a Mavic Pro camera module:

./dji_imah_fwsig.py -vv -k PRAK-2017-01 -k PUEK-2017-07 -u -i wm220_0101_v02.00.55.69_20161215.pro.fw.sig

Un-signing a Phantom 4 Pro V2 flight controller module:

./dji_imah_fwsig.py -vv -k PRAK-2017-01 -k PUEK-2017-07 -u -i wm335_0306_v03.03.04.10_20180429.pro.fw.sig

Re-signing requires the private part of the key, which is generally not available for consumer-grade DJI products.

Flight Controller Parameter Tools

Beyond firmware extraction, the repository includes tools for modifying flight controller behavior without re-flashing firmware. The `dji_flyc_param_ed.py` script edits flight controller parameters. The `dji_flyc_hardcoder.py` script hardcodes specific values in the firmware binary. The `dji_flyc_nofly_ed.py` script edits no-fly zone data.

Product communication tools allow direct interaction with a connected drone over serial or I2C. The `comm_serialtalk.py` and `comm_og_service_tool.py` scripts send commands and receive responses. The `comm_sbs_bqctrl.py` script communicates with smart battery controllers. The `comm_mkdupc.py` and `comm_dat2pcap.py` scripts create and convert DUP communication packets and DAT log files respectively.

Running these tools requires connecting the drone to a PC via serial interface. The README notes that to get specifics on command-line arguments, each tool should be run with the `--help` option. Some tools have additional remarks in their headers when viewed directly.

Limitations and the Signing Problem

The most significant practical limitation is firmware signing. Newer DJI products use asymmetric cryptography to sign firmware packages. Re-packing a modified module into a flashable package requires signing it with the correct private key. DJI does not publish those keys, and the project has only the public keys needed for verification and decryption of distribution packages. This means full round-trip modification and reflashing is not possible for products where signed firmware cannot be bypassed.

The README notes that bypassing firmware signing sometimes requires additional steps such as rooting the drone. The details of how to do this for specific products are beyond the scope of the tools and are not documented in the repository itself.

The tools are Python scripts without a graphical interface, a package installer, or a version management system for the scripts themselves. The repository has no releases; the master branch is the current version. The source code itself is the format documentation: the README directs users to read the source to understand protocol and format details.

A comparison: DJI Assistant 2 is the official application that exposes parameter configuration and firmware updates for supported DJI products. It covers the use cases DJI chooses to expose, with hardware compatibility limited to supported products and software limited to what DJI implements. dji-firmware-tools covers what is technically accessible at the binary and protocol level, but requires engineering knowledge to use safely.

Repository Layout, Tests, and License

The repository contains approximately 20 Python scripts at the top level, alongside a `comm_dissector/` directory for communication dissector plugins, a `comm_sbs_chips/` directory for smart battery chip definitions, and a `symbols/` directory for pre-defined symbol tables used in disassembly. The `supported_firmwares_xv4.csv` file lists the firmware packages that the xV4 container tool has been verified against.

A `tests/` directory exists and the README recommends looking at the tests to find command-line examples for communicating with specific drones or extracting specific firmware generations. The tests function as working examples rather than automated regression tests.

The project is licensed under GPL-3.0. The source code used as format documentation is consistent with this license: if the tools are modified and distributed, the source must remain available. The last push was on 2026-07-21.

Editorial conclusion

dji-firmware-tools is appropriate for hardware engineers, security researchers, and repair technicians who need to inspect or modify DJI firmware at a level the official DJI Assistant software does not expose. The README explicitly states the tools are for engineers with hardware and software knowledge and warns against use by those who do not understand what they are doing. Some firmware packages are signed with asymmetric cryptography, and private keys for re-signing are not generally available, which limits full round-trip modification for newer products. The last push was on 2026-07-21 and the repository is licensed under GPL-3.0.

Frequently asked questions

Official sources

1. Official README
2. Project repository