cd900a8973
* fix(mavlink): reject unsupported params in commands and missions PX4 accepted any non-NaN value in params it does not use for a given MAV_CMD, silently storing or ignoring them. This made it impossible for a GCS to detect that a mission item or command was malformed, and risked unexpected behaviour if the param meaning is assigned in a future update. Add mavlink_command_params.h: a header-only sorted lookup table mapping each supported MAV_CMD to uint8 bitmasks (one for mission items, one for commands) indicating which of params 1-4 are valid. check_params() does a binary search and returns the 1-based index of the first offending param, or 0 if all unsupported params are unset. A param is considered unset when it is NaN (the MAVLink standard) or 0.0 (the conventional GCS default for unused float fields). Any other value in an unsupported slot is rejected: - Mission uploads (MISSION_ITEM / MISSION_ITEM_INT): NACK with MAV_MISSION_INVALID_PARAMn for the offending param index. - Commands (COMMAND_LONG / COMMAND_INT): ACK with MAV_RESULT_DENIED. Validation is placed at the MAVLink ingress boundary (parse_mavlink_mission_item and handle_message_command_both) before any downstream processing, keeping Commander and Navigator unmodified. The table covers all 45 MAV_CMDs handled by PX4's mission and command parsers. The static_assert enforces sort order at compile time. Fixes #27483 Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): split mission/command p5-7 masks, fix int_mode branch, add vehicle overrides Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): fix 142-char lines and Python CI type/style errors Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): pack p5-7 bits into mission/command byte, fix astyle/type-limits/mypy * fix(mavlink): range-for over VehicleParamOverrides, fix mypy ignore code * fix(mavlink): wire check_params_for_vehicle, add int variant, drop non-vehicle check_params Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): suppress clang unused-function on check_params_*_for_vehicle Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): rename local vs to avoid shadow in handle_message_command_both Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): cache vehicle_type_bitmask as member, update on vehicle_status change Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): use named VEHICLE_TYPE_* consts, fix masks, drop WARN spam, fix int_mode cast Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): normalize INT32_MAX to 0 for MAV_FRAME_MISSION p5/p6 in int_mode For MAV_FRAME_MISSION items, x/y are generic p5/p6 params (not lat/lon), so GCS tools send 0 for unused params — not INT32_MAX. Using check_params_int_for_vehicle here caused int_param_is_unset(0)=false, which rejected valid DO_LAND_START and similar items with x=y=0. Fix by normalizing INT32_MAX to 0.0f before calling check_params_for_vehicle, so both the MISSION_ITEM_INT sentinel and the conventional float zero are treated as unset. This restores acceptance of zero-param items like DO_LAND_START while still correctly rejecting items that carry non-zero, non-sentinel values in unsupported param slots. Signed-off-by: Himaghna <pen314paper@gmail.com> * fix(mavlink): address review feedback on VTOL masks, NaN sentinel, dead enum, and RTL test frame * fix(mavlink): move param validation test out of mavsdk_tests, rename header to .hpp * fix(mavlink): dedupe param-scan loop shared by check_params_for_vehicle variants --------- Signed-off-by: Himaghna <pen314paper@gmail.com>
The autopilot stack the industry builds on.
About
PX4 is an open-source autopilot stack for drones and unmanned vehicles. It supports multirotors, fixed-wing, VTOL, rovers, and many more experimental platforms from racing quads to industrial survey aircraft. It runs on NuttX, Linux, and macOS. Licensed under BSD 3-Clause.
Why PX4
Modular architecture. PX4 is built around uORB, a DDS-compatible publish/subscribe middleware. Modules are fully parallelized and thread safe. You can build custom configurations and trim what you don't need.
Wide hardware support. PX4 runs on a wide range of autopilot boards and supports an extensive set of sensors, telemetry radios, and actuators through the Pixhawk ecosystem.
Developer friendly. First-class support for MAVLink and DDS / ROS 2 integration. Comprehensive SITL simulation, hardware-in-the-loop testing, and log analysis tools. An active developer community on Discord and the weekly dev call.
Vendor neutral governance. PX4 is hosted under the Dronecode Foundation, part of the Linux Foundation. Business-friendly BSD-3 license. No single vendor controls the roadmap.
Supported Vehicles
 Multicopter |
 Fixed Wing |
 VTOL |
 Rover |
…and many more: helicopters, autogyros, airships, submarines, boats, and other experimental platforms. These frames have basic support but are not part of the regular flight-test program. See the full airframe reference.
Try PX4
Run PX4 in simulation with a single command. No build tools, no dependencies beyond Docker:
docker run --rm -it -p 14550:14550/udp px4io/px4-sitl:latest
Open QGroundControl and fly. See PX4 Simulation Quickstart for more options.
Build from Source
git clone https://github.com/PX4/PX4-Autopilot.git --recursive
cd PX4-Autopilot
make px4_sitl
Note
See the Development Guide for toolchain setup and build options.
Documentation & Resources
| Resource | Description |
|---|---|
| User Guide | Build, configure, and fly with PX4 |
| Developer Guide | Modify the flight stack, add peripherals, port to new hardware |
| Airframe Reference | Full list of supported frames |
| Autopilot Hardware | Compatible flight controllers |
| Release Notes | What's new in each release |
| Contribution Guide | How to contribute to PX4 |
Community
- Weekly Dev Call — open to all developers (Dronecode calendar)
- Discord — Join the Dronecode server
- Discussion Forum — PX4 Discuss
- Maintainers — see
MAINTAINERS.md - Contributor Stats — LFX Insights
Contributing
We welcome contributions of all kinds — bug reports, documentation, new features, and code reviews. Please read the Contribution Guide to get started.
Citation
If you use PX4 in academic work, please cite it. BibTeX:
@software{px4_autopilot,
author = {Meier, Lorenz and {The PX4 Contributors}},
title = {{PX4 Autopilot}},
publisher = {Zenodo},
doi = {10.5281/zenodo.595432},
url = {https://px4.io}
}
The DOI above is a Zenodo concept DOI that always resolves to the latest release. For a version-pinned citation, see the Zenodo record or our CITATION.cff.
Governance
The PX4 Autopilot project is hosted by the Dronecode Foundation, a Linux Foundation Collaborative Project. Dronecode holds all PX4 trademarks and serves as the project's legal guardian, ensuring vendor-neutral stewardship — no single company owns the name or controls the roadmap. The source code is licensed under the BSD 3-Clause license, so you are free to use, modify, and distribute it in your own projects.
