devices-metadata: Generate metadata using the modules system

modules/devices-metadata.nix

@@ -0,0 +1,30 @@
+{ config, pkgs, ... }:
+
+let
+  inherit (config) mobile;
+  inherit (mobile.device) info;
+in
+{
+
+  # The device-metadata output is used internally by the documentation
+  # generation to generate the per-device pages.
+  # Assume this format is fluid and will change.
+  system.build.device-metadata = pkgs.writeTextFile {
+    name = "${mobile.device.name}-metadata";
+    destination = "/${mobile.device.name}.json";
+    text = (builtins.toJSON {
+      inherit (info) name;
+      inherit (mobile) hardware;
+      system = {
+        inherit (mobile.system) type system;
+      };
+
+      manufacturer = if info ? manufacturer then info.manufacturer else "N/A";
+      identifier = mobile.device.name;
+
+      fullName = if info ? manufacturer
+        then "${info.manufacturer} ${info.name}"
+        else info.name;
+    });
+  };
+}

modules/module-list.nix

@@ -9,6 +9,7 @@
   ./adb.nix
   ./boot-initrd.nix
   ./cross-workarounds.nix
+  ./devices-metadata.nix
   ./hardware-allwinner.nix
   ./hardware-generic.nix
   ./hardware-qualcomm.nix