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/mail/opensmtpd.nix

@@ -0,0 +1,135 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.opensmtpd;
+  conf = pkgs.writeText "smtpd.conf" cfg.serverConfiguration;
+  args = concatStringsSep " " cfg.extraServerArgs;
+
+  sendmail = pkgs.runCommand "opensmtpd-sendmail" { preferLocalBuild = true; } ''
+    mkdir -p $out/bin
+    ln -s ${cfg.package}/sbin/smtpctl $out/bin/sendmail
+  '';
+
+in {
+
+  ###### interface
+
+  imports = [
+    (mkRenamedOptionModule [ "services" "opensmtpd" "addSendmailToSystemPath" ] [ "services" "opensmtpd" "setSendmail" ])
+  ];
+
+  options = {
+
+    services.opensmtpd = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to enable the OpenSMTPD server.";
+      };
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.opensmtpd;
+        defaultText = literalExpression "pkgs.opensmtpd";
+        description = "The OpenSMTPD package to use.";
+      };
+
+      setSendmail = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Whether to set the system sendmail to OpenSMTPD's.";
+      };
+
+      extraServerArgs = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        example = [ "-v" "-P mta" ];
+        description = ''
+          Extra command line arguments provided when the smtpd process
+          is started.
+        '';
+      };
+
+      serverConfiguration = mkOption {
+        type = types.lines;
+        example = ''
+          listen on lo
+          accept for any deliver to lmtp localhost:24
+        '';
+        description = ''
+          The contents of the smtpd.conf configuration file. See the
+          OpenSMTPD documentation for syntax information.
+        '';
+      };
+
+      procPackages = mkOption {
+        type = types.listOf types.package;
+        default = [];
+        description = ''
+          Packages to search for filters, tables, queues, and schedulers.
+
+          Add OpenSMTPD-extras here if you want to use the filters, etc. from
+          that package.
+        '';
+      };
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf cfg.enable rec {
+    users.groups = {
+      smtpd.gid = config.ids.gids.smtpd;
+      smtpq.gid = config.ids.gids.smtpq;
+    };
+
+    users.users = {
+      smtpd = {
+        description = "OpenSMTPD process user";
+        uid = config.ids.uids.smtpd;
+        group = "smtpd";
+      };
+      smtpq = {
+        description = "OpenSMTPD queue user";
+        uid = config.ids.uids.smtpq;
+        group = "smtpq";
+      };
+    };
+
+    security.wrappers.smtpctl = {
+      owner = "root";
+      group = "smtpq";
+      setuid = false;
+      setgid = true;
+      source = "${cfg.package}/bin/smtpctl";
+    };
+
+    services.mail.sendmailSetuidWrapper = mkIf cfg.setSendmail
+      (security.wrappers.smtpctl // { program = "sendmail"; });
+
+    systemd.tmpfiles.rules = [
+      "d /var/spool/smtpd 711 root - - -"
+      "d /var/spool/smtpd/offline 770 root smtpq - -"
+      "d /var/spool/smtpd/purge 700 smtpq root - -"
+    ];
+
+    systemd.services.opensmtpd = let
+      procEnv = pkgs.buildEnv {
+        name = "opensmtpd-procs";
+        paths = [ cfg.package ] ++ cfg.procPackages;
+        pathsToLink = [ "/libexec/opensmtpd" ];
+      };
+    in {
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+      serviceConfig.ExecStart = "${cfg.package}/sbin/smtpd -d -f ${conf} ${args}";
+      environment.OPENSMTPD_PROC_PATH = "${procEnv}/libexec/opensmtpd";
+    };
+  };
+}