The nested CycloneDDS CMake invocation in msg/CMakeLists.txt exists
only to produce the 'idlc' IDL compiler as a host-side code-gen
tool. It does not need CycloneDDS's TLS transport or DDS Security
features, but both default to ON in cyclonedds' upstream CMake.
When ENABLE_SSL=AUTO (the default), cyclonedds finds the system
OpenSSL and builds ddsi_ssl.c. On macos-latest the system OpenSSL
is 3.x, which removed the deprecated SSL_get_peer_certificate()
symbol used in our pinned cyclonedds revision (2023). The host
build then fails at link time with:
Undefined symbols for architecture arm64:
"_SSL_get_peer_certificate", referenced from:
_dds_report_tls_version in ddsi_ssl.c.o
This broke every Zenoh-enabled board build on macOS (boards that
select CONFIG_MODULES_ZENOH pull in LIB_CDRSTREAM, which is what
triggers the nested build). v5 and v6x never hit it because they
don't enable Zenoh.
Passing -DENABLE_SSL=OFF -DENABLE_SECURITY=OFF skips compilation of
ddsi_ssl.c and the security plugins entirely. idlc is unaffected
(pure C code generation, no DDS runtime).
Verified locally on macOS ARM64: clean distclean + make
px4_fmu-v6xrt_default completes in 2090/2090 ninja steps, producing
a 2.1 MB .px4 with 59% FLASH used.
Signed-off-by: Ramon Roche <mrpollo@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.