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/network-filesystems/davfs2.nix

@@ -0,0 +1,93 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.davfs2;
+  cfgFile = pkgs.writeText "davfs2.conf" ''
+    dav_user ${cfg.davUser}
+    dav_group ${cfg.davGroup}
+    ${cfg.extraConfig}
+  '';
+in
+{
+  options.services.davfs2 = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to enable davfs2.
+      '';
+    };
+
+    davUser = mkOption {
+      type = types.str;
+      default = "davfs2";
+      description = ''
+        When invoked by root the mount.davfs daemon will run as this user.
+        Value must be given as name, not as numerical id.
+      '';
+    };
+
+    davGroup = mkOption {
+      type = types.str;
+      default = "davfs2";
+      description = ''
+        The group of the running mount.davfs daemon. Ordinary users must be
+        member of this group in order to mount a davfs2 file system. Value must
+        be given as name, not as numerical id.
+      '';
+    };
+
+    extraConfig = mkOption {
+      type = types.lines;
+      default = "";
+      example = ''
+        kernel_fs coda
+        proxy foo.bar:8080
+        use_locks 0
+      '';
+      description = ''
+        Extra lines appended to the configuration of davfs2.
+      ''  ;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ pkgs.davfs2 ];
+    environment.etc."davfs2/davfs2.conf".source = cfgFile;
+
+    users.groups = optionalAttrs (cfg.davGroup == "davfs2") {
+      davfs2.gid = config.ids.gids.davfs2;
+    };
+
+    users.users = optionalAttrs (cfg.davUser == "davfs2") {
+      davfs2 = {
+        createHome = false;
+        group = cfg.davGroup;
+        uid = config.ids.uids.davfs2;
+        description = "davfs2 user";
+      };
+    };
+
+    security.wrappers."mount.davfs" = {
+      program = "mount.davfs";
+      source = "${pkgs.davfs2}/bin/mount.davfs";
+      owner = "root";
+      group = cfg.davGroup;
+      setuid = true;
+      permissions = "u+rx,g+x";
+    };
+
+    security.wrappers."umount.davfs" = {
+      program = "umount.davfs";
+      source = "${pkgs.davfs2}/bin/umount.davfs";
+      owner = "root";
+      group = cfg.davGroup;
+      setuid = true;
+      permissions = "u+rx,g+x";
+    };
+
+  };
+
+}