DFU stands for „Device Firmware Update“ and is a technology used to upgrade the firmware of embedded devices like lighting fixtures, sensors, or controllers. This process is crucial for fixing bugs, improving functionality, adding new features, and patching security vulnerabilities after the devices have been deployed.
The Vision DFU (Device Firmware Update) process involves just sending a variable sized datastream to the device. This raw datastream does not have a defined structure, which means it can work with all previous fixture DFUs. This flexibility allows any type of DFU file to be used, making it easier to update devices without needing to change the file format. To get the update data to the app a simple „.bin“ file is used. It is recommended that error checks are implemented in the data stream.
A DFU file („.bin“ file / datastream) contains the data necessary to update the firmware of an embedded device. The structure of a DFU file is designed to ensure that the firmware can be safely and effectively updated. An important aspect of this structure is the inclusion of a header, which carries specific information that helps in managing the update process. Here’s how the components typically work together:
Components of a DFU Binary File with Header:
- Header: The header is a crucial part of the DFU file as it contains metadata about the firmware update. This metadata typically includes:
- Version number: Indicates the version of the firmware, helping to determine if the update is newer than the current firmware on the device.
- Device identifier: Specifies the types of devices that are compatible with the firmware, ensuring that the update is applied only to appropriate devices.
- Checksum or hash: A cryptographic hash of the firmware data, used to verify the integrity of the file after it has been downloaded or transferred, to ensure it has not been tampered with or corrupted.
- Firmware Data: This is the actual binary data that will be written to the device’s memory. It replaces the existing firmware or modifies parts of it to enhance functionality or fix issues.