# Air Firmware Loader The firmware loader is a self-contained minimal program which allows for receiving firmware update images over the air. The received images are stored in flash memory and after a reboot the second stage bootloader validates and installs the image. Generally the firmware loader should not be used in normal operation of Ruuvi Air, it is a backup option for recovery update in case a firmware update breaks the main application somehow. If both main application and firmware loader are broken, a factory reset can be executed by holding down button on Ruuvi Air for at least 15 seconds. After factory reset, the device is back to initial state and can receive the updates. The source code is available at --- # 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.ruuvi.com/ruuvi-air-firmware/air-firmware-loader.md?ask= ``` 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.