New configuration initial commit

devices/default/default.nix

@@ -0,0 +1,33 @@
+# Edit this configuration file to define what should be installed on
+# your system.  Help is available in the configuration.nix(5) man page
+# and in the NixOS manual (accessible by running ‘nixos-help’).
+
+{ config, pkgs, lib, ... }:
+
+{
+  imports = [ # Include the results of the hardware scan.
+    ./hardware-configuration.nix
+  ];
+
+  systemd.services.limitbat0 = let bat0_charge_limit = 80;
+  in {
+    enable = true;
+    description = "Limit battry charge to 80%";
+    unitConfig = { After = "multi-user.target"; };
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = "/bin/sh -c 'echo ${
+          toString bat0_charge_limit
+        } > /sys/class/power_supply/BAT0/charge_control_end_threshold'";
+    };
+    wantedBy = [ "multi-user.target" ];
+  };
+
+  swapDevices = [{
+    device = "/var/lib/swapfile";
+    size = 16 * 1024;
+  }];
+  boot.initrd.systemd.enable = true;
+
+}
+