# Firmware

H-Flow runs the [PX4 DroneCAN Firmware](https://docs.px4.io/main/en/dronecan/px4_cannode_fw.html). It supports firmware updates over the CAN bus and [dynamic node allocation](https://docs.px4.io/main/en/dronecan/).

H-Flow boards ship with 1.15 or later firmware pre-installed, but if you want to build and flash the latest firmware yourself. See [PX4 DroneCAN Firmware > Building the Firmware](https://docs.px4.io/main/en/dronecan/px4_cannode_fw.html).

* Firmware target: holybro\_h-flow\_default
* Bootloader target: holybro\_h-flow\_canbootloader

## Firmware Update[​](https://docs.px4.io/main/en/dronecan/)

PX4 can upgrade device firmware over DroneCAN. To upgrade the device, all you need to do is copy the firmware binary into the root directory of the flight controller's SD card and reboot.

Upon boot, the flight controller will automatically transfer the firmware onto the device and upgrade it. If successful, the firmware binary will be removed from the root directory and there will be a file named **XX.bin** in the **/ufw** directory of the SD card.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.holybro.com/peripherals/h-flow-dronecan/firmware.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.