PX4 Bootloader is a bootloader for legacy STM32F1, F3, F4, and F7 microcontrollers used in PX4 autopilot hardware including PX4FMU, PX4IO, and PX4FLOW boards.
The bootloader enables firmware updates on embedded flight control systems by implementing a protocol-based upgrade mechanism. It requires specific handshake sequences before accepting critical operations like chip erasure or boot commands, preventing accidental firmware corruption. The tool supports building both ELF files for JTAG adapters and BIN files for direct onboard flashing, with separate build targets for different board types.
This project is relevant for developers maintaining or deploying PX4-based autopilot systems on the supported STM32 generations. It suits teams working with legacy PX4 hardware that cannot migrate to newer STM32H7 variants, which have moved their bootloaders into the main PX4 autopilot repository. The repository also maintains a board types registry kept synchronized with ArduPilot's equivalent list, serving as a reference for hardware identification across both projects.
The project receives infrequent updates focused on maintaining compatibility with existing hardware rather than adding new features. Development activity centers on preserving bootloader functionality for legacy boards and keeping board identification metadata current across the PX4 and ArduPilot ecosystems.
