183b3e38d5
* fix(bootloader): scrub uncorrectable flash ECC errors on STM32H7 before boot A torn write to a flash row (power lost mid program/erase) can leave it with inconsistent ECC. On H7 a CPU read of such a row raises an uncorrectable double-bit ECC error -> bus fault, so the application hard faults on every boot before printing anything, and only a mass erase recovers it: reflashing does not, because neither the app nor the bootloader image touches the parameter sector. Scan the application and parameter flash with DMA right after clock_init (a DMA read latches FLASH_SR DBECCERR instead of bus-faulting the CPU) and erase any sector that holds an uncorrectable error. A corrupt parameter sector then re-seeds to defaults on the next app boot; corrupt app flash fails the image check and stays in the bootloader for reflash. Mirrors ArduPilot's bootloader ECC scrub. H7-gated; the scan runs before the interface DMA is brought up, so DMA1 stream 0 is uncontended. * test(tools): add STM32H7 flash ECC fault injection tool A bench helper that deterministically plants an uncorrectable (double-bit) flash ECC error on an STM32H7, reproducing the torn-write parameter-store brick. Used to validate the bootloader ECC scrub and the parameter re-seed recovery on hardware: plant the fault, then confirm the board boots clean instead of hard-faulting every boot. brick_ecc.c is a freestanding stub that double-programs one flash word with two different single-bit clears (the recipe that yields an inconsistent ECC); brick_ecc.sh builds it, loads it into AXI SRAM over ST-Link, runs it, and resets the board. README documents usage and how to retarget another board. * fix(bootloader): require DMA transfer-complete for a clean ECC scan chunk The stream self-disables on both transfer-complete and transfer-error. A non-ECC bus error (unreachable scan buffer, rejected FIFO config) previously read as a clean chunk, silently turning the scan into a no-op. Require TCIF so an unread chunk takes the skip-the-scan fallback instead of passing. Signed-off-by: Jacob Dahl <dahl.jakejacob@gmail.com> --------- Signed-off-by: Jacob Dahl <dahl.jakejacob@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.
