uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/networking/atftpd.nix

@@ -0,0 +1,65 @@
+# NixOS module for atftpd TFTP server
+
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.atftpd;
+
+in
+
+{
+
+  options = {
+
+    services.atftpd = {
+
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = ''
+          Whether to enable the atftpd TFTP server. By default, the server
+          binds to address 0.0.0.0.
+        '';
+      };
+
+      extraOptions = mkOption {
+        default = [];
+        type = types.listOf types.str;
+        example = literalExpression ''
+          [ "--bind-address 192.168.9.1"
+            "--verbose=7"
+          ]
+        '';
+        description = ''
+          Extra command line arguments to pass to atftp.
+        '';
+      };
+
+      root = mkOption {
+        default = "/srv/tftp";
+        type = types.path;
+        description = ''
+          Document root directory for the atftpd.
+        '';
+      };
+
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+
+    systemd.services.atftpd = {
+      description = "TFTP Server";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      # runs as nobody
+      serviceConfig.ExecStart = "${pkgs.atftp}/sbin/atftpd --daemon --no-fork ${lib.concatStringsSep " " cfg.extraOptions} ${cfg.root}";
+    };
+
+  };
+
+}