This flake exposes a set of utilities to manage QMK firmwares as stand-alone repositories (possibly flakes) using Nix.

Usage

The flake has only one single output i.e. utils-factory which takes the following parameters:

{
  src # local path with the firmware source (the directory normally inside $QMK_HOME/keyboards/)
, keyboard-name # name of the keyboard (the name of the directory inside $QMK_HOME/keyboards/)
, keymap-name # name of the keymap
, flash-script ? null # needed only for flashing using the "flasher" output
, extra-build-inputs ? [ ] # extra dependencies needed during the build
, qmk-firmware-source ? qmk-firmware-default-source # the "qmk_firmware" that will be used
, avr ? true # these may be needed according the target architecture (used in the devShell)
, arm ? true
, teensy ? true
}

The following parameters may require a better explanation:

flash-script

It’s a string containing a bash script that flash the firmare on the device. The $HEX_FILE variable is accessible in the script and its value is the path of the compiled binary (.hex) firmware.

If you don’t pass flash-script you will not be able to use the flasher ouput.

An example to flash atmega32u4:

echo -n "Press the RESET button..."

while [ ! -e /dev/ttyACM0 ]
do
    echo -n "."
    sleep 0.5
done

${pkgs.avrdude}/bin/avrdude -p atmega32u4 -c avr109 -P /dev/ttyACM0 -U flash:w:$HEX_FILE

qmk-firmware-source

The qmk_firmware repository internally cloned, the default value is the one defined in the utils/qmk-firmware.json file. If you want you can override this value passing another version, or, for example if you want to use the QMK fork with Vial you could use:

# qmk-vial-source =
pkgs.fetchFromGitHub {
  owner = "vial-kb";
  repo = "vial-qmk";
  rev = "adef73a79068c538161268dbda67f0681468a782";
  sha256 = "sha256-kGdNyMMMnYjglU9QeFrSHdZHEM7KX2Om84PYBQZbSQg=";
  fetchSubmodules = true;
}

However, utils-factory returns an attrset (called utils) containing the following utilities:

hex

This derivation contains the compiled `.hex` binary.

flasher

This application is a shell script that flash the firmware. It simply executes the flash-script. parameterizing it with the firmare binary. The logic to manage any waiting for the device to be ready to be flashed must be part of flash-script.

dev-shell

If this flake is used in its turn by another flake, it’s possible to set the devShell output as this dev-shell to have fast development environment (with nix develop). This is done by making the shell automatically clone a copy of qmk-firmare-source locally (.qmk_firmware/) and linking the firmware source directory to ./qmk_firmware/keyboards/<keyboard-name>.

Examples

You can see this utilities in action in my macropad repository.

If your project uses this flake, please make a PR to add your example of use here.