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/gvpe.nix

@@ -0,0 +1,130 @@
+# GNU Virtual Private Ethernet
+
+{config, pkgs, lib, ...}:
+
+let
+  inherit (lib) mkOption mkIf types;
+
+  cfg = config.services.gvpe;
+
+  finalConfig = if cfg.configFile != null then
+    cfg.configFile
+  else if cfg.configText != null then
+    pkgs.writeTextFile {
+      name = "gvpe.conf";
+      text = cfg.configText;
+    }
+  else
+    throw "You must either specify contents of the config file or the config file itself for GVPE";
+
+  ifupScript = if cfg.ipAddress == null || cfg.subnet == null then
+     throw "Specify IP address and subnet (with mask) for GVPE"
+   else if cfg.nodename == null then
+     throw "You must set node name for GVPE"
+   else
+   (pkgs.writeTextFile {
+    name = "gvpe-if-up";
+    text = ''
+      #! /bin/sh
+
+      export PATH=$PATH:${pkgs.iproute2}/sbin
+
+      ip link set $IFNAME up
+      ip address add ${cfg.ipAddress} dev $IFNAME
+      ip route add ${cfg.subnet} dev $IFNAME
+
+      ${cfg.customIFSetup}
+    '';
+    executable = true;
+  });
+in
+
+{
+  options = {
+    services.gvpe = {
+      enable = lib.mkEnableOption "gvpe";
+
+      nodename = mkOption {
+        default = null;
+        type = types.nullOr types.str;
+        description =''
+          GVPE node name
+        '';
+      };
+      configText = mkOption {
+        default = null;
+        type = types.nullOr types.lines;
+        example = ''
+          tcp-port = 655
+          udp-port = 655
+          mtu = 1480
+          ifname = vpn0
+
+          node = alpha
+          hostname = alpha.example.org
+          connect = always
+          enable-udp = true
+          enable-tcp = true
+          on alpha if-up = if-up-0
+          on alpha pid-file = /var/gvpe/gvpe.pid
+        '';
+        description = ''
+          GVPE config contents
+        '';
+      };
+      configFile = mkOption {
+        default = null;
+        type = types.nullOr types.path;
+        example = "/root/my-gvpe-conf";
+        description = ''
+          GVPE config file, if already present
+        '';
+      };
+      ipAddress = mkOption {
+        default = null;
+        type = types.nullOr types.str;
+        description = ''
+          IP address to assign to GVPE interface
+        '';
+      };
+      subnet = mkOption {
+        default = null;
+        type = types.nullOr types.str;
+        example = "10.0.0.0/8";
+        description = ''
+          IP subnet assigned to GVPE network
+        '';
+      };
+      customIFSetup = mkOption {
+        default = "";
+        type = types.lines;
+        description = ''
+          Additional commands to apply in ifup script
+        '';
+      };
+    };
+  };
+  config = mkIf cfg.enable {
+    systemd.services.gvpe = {
+      description = "GNU Virtual Private Ethernet node";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+
+      preStart = ''
+        mkdir -p /var/gvpe
+        mkdir -p /var/gvpe/pubkey
+        chown root /var/gvpe
+        chmod 700 /var/gvpe
+        cp ${finalConfig} /var/gvpe/gvpe.conf
+        cp ${ifupScript} /var/gvpe/if-up
+      '';
+
+      script = "${pkgs.gvpe}/sbin/gvpe -c /var/gvpe -D ${cfg.nodename} "
+        + " ${cfg.nodename}.pid-file=/var/gvpe/gvpe.pid"
+        + " ${cfg.nodename}.if-up=if-up"
+        + " &> /var/log/gvpe";
+
+      serviceConfig.Restart = "always";
+    };
+  };
+}