NRF52 Desktop DFU

A cross-platform library to perform device firmware upgrades (DFU) for Nordic's NRF52 devices. The API is straightforward and agnostic to the BLE implementation, giving developers a quick way to carry out a DFU from a desktop environment.

Code Structure

• src-dfu
  • An API that is agnostic to the BLE implementation (NrfDfuServer)
• src-dfu-app
  • A small console application that uses the compiled src-dfu library.

Build Instructions

We have specific scripts to compile the library on each platform. All binaries will be placed in the bin folder.

Windows

• Install Visual Studio 2019, selecting the C++ toolchain.
• Install CMake from https://cmake.org/
• Run .\toolchains\windows\windows_compile.bat from Powershell.
  • Use -c or -clean to perform a full rebuild of the project.
  • Use -a=<ARCH> or -arch=<ARCH> to build the libraries for a specific architecture. (Supported values are x86 and x64.)

Linux

• Run ./toolchains/linux/linux_install.sh to install the OS dependencies. This should be required only once.
• Run ./toolchains/linux/linux_compile.sh to build the project.
  • Use -c or -clean to perform a full rebuild of the project.

macOS

• Install Homebrew from https://brew.sh/
• Run brew install cmake to install CMake.
• Run ./toolchains/macos/macos_compile.sh to build the project.
  • Use -c or -clean to perform a full rebuild of the project. The library will be compiled into a .dylib and saved into bin/darwin.

Usage of the DFU application.

To perform a DFU with the bundled application that we developed, the following information and files are needed:

• The MAC address of the device (when booted in DFU mode) to be upgraded.
• Zip file containing everything for the upgrade:
  • Data File (.dat): This file contains the image type, the image cryptographic hash, etc.
  • Binary File (.bin): Application to be uploaded to the device.
  • JSON Manifest (.json): Specifies which file is which for this to work.

Usage: dfu_app.exe <mac_address> <dfu_zip_path>

• : Device MAC address in a format compatible with the BLE library. (See note for how macOS handles MAC addresses)
• : Path to the DFU zip package

Windows Example

• Run .\bin\windows-x64\dfu_app.exe EE4200000000 package.zip

Linux Example

• Run ./bin/linux/dfu_app EE:42:00:00:00:00 package.zip

MacOS Example

• Run ./bin/darwin/dfu_app {UUID} package.zip

Important Notes

Functionality

• This library is focused on providing upgrade functionality when using Nordic's Secure DFU Bootloader. Some part of the internal logic is hard-coded around this, so it's possible it won't work for a passwordless DFU. We might add this functionality in the future!
• Current upgrades are not resumable. If something fails during the process, the library might fail or crash, requiring a complete restart of the process.

macOS - MAC Addresses and UUIDs

In an effort to protect privacy, CoreBluetooth (the underlying macOS Bluetooth API) does not expose the MAC address of a device to a user. Instead, it randomizes the MAC address to a UUID (Universal Unique Identifier) that is exposed to the user. Instead, you will need to scan for devices and find the UUID of the desired device to connect to.

License

All components within this project that have not been bundled from external creators, are licensed under the terms of the MIT Licence.