diff --git a/firmware/.envrc b/firmware/.envrc
new file mode 100644
index 0000000..29316ce
--- /dev/null
+++ b/firmware/.envrc
@@ -0,0 +1 @@
+use flake ..#firmware --override-input rootdir "file+file://"<(printf %s "$PWD")
diff --git a/firmware/.gitignore b/firmware/.gitignore
new file mode 100644
index 0000000..c4a847d
--- /dev/null
+++ b/firmware/.gitignore
@@ -0,0 +1 @@
+/result
diff --git a/firmware/base.nix b/firmware/base.nix
new file mode 100644
index 0000000..16f3ac4
--- /dev/null
+++ b/firmware/base.nix
@@ -0,0 +1,19 @@
+{ lib, ... }:
+let
+  inherit (lib) mkOption;
+in
+{
+  options.my.build = {
+    image = mkOption {
+      description = "Final output image for distribution.";
+      type = lib.types.unspecified;
+    };
+  };
+
+  config = {
+    system = {
+      stateVersion = "24.11";
+    };
+  };
+}
+
diff --git a/firmware/default.nix b/firmware/default.nix
new file mode 100644
index 0000000..5ff893e
--- /dev/null
+++ b/firmware/default.nix
@@ -0,0 +1,32 @@
+{ inputs, ... }:
+let
+  mkSystem = target: inputs.nixpkgs.lib.nixosSystem {
+    modules = [
+      ./base.nix
+      target
+    ];
+  };
+in
+{
+  flake.nixosConfigurations = {
+    qclk-rpi3 = mkSystem target/rpi3.nix;
+  };
+
+  perSystem = { libMy, pkgs, ... }: {
+    devenv.shells.firmware = libMy.withRootdir {
+      packages = with pkgs; [
+        nixos-rebuild
+        nixVersions.latest
+      ];
+
+      scripts = {
+        build.exec = ''
+          nix build "..#nixosConfigurations.qclk-$1.config.system.build.toplevel"
+        '';
+        build-image.exec = ''
+          nix build "..#nixosConfigurations.qclk-$1.config.my.build.image"
+        '';
+      };
+    };
+  };
+}
diff --git a/firmware/target/rpi3.nix b/firmware/target/rpi3.nix
new file mode 100644
index 0000000..62a5961
--- /dev/null
+++ b/firmware/target/rpi3.nix
@@ -0,0 +1,8 @@
+{ pkgs, modulesPath, config, ... }: {
+  imports = [
+    "${modulesPath}/installer/sd-card/sd-image-aarch64.nix"
+  ];
+
+  nixpkgs.system = "aarch64-linux";
+  my.build.image = config.system.build.sdImage;
+}
diff --git a/flake.nix b/flake.nix
index 2ed3d5c..6e44b9b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -16,6 +16,7 @@
         devenv.flakeModule
 
         ./mcu
+        ./firmware
       ];
       systems = [ "x86_64-linux" ];