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/system/earlyoom.nix

@@ -0,0 +1,160 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.earlyoom;
+
+  inherit (lib)
+    mkDefault mkEnableOption mkIf mkOption types
+    mkRemovedOptionModule literalExpression
+    escapeShellArg concatStringsSep optional optionalString;
+
+in
+{
+  options.services.earlyoom = {
+    enable = mkEnableOption "Early out of memory killing";
+
+    freeMemThreshold = mkOption {
+      type = types.ints.between 1 100;
+      default = 10;
+      description = ''
+        Minimum available memory (in percent).
+
+        If the available memory falls below this threshold (and the analog is true for
+        <option>freeSwapThreshold</option>) the killing begins.
+        SIGTERM is sent first to the process that uses the most memory; then, if the available
+        memory falls below <option>freeMemKillThreshold</option> (and the analog is true for
+        <option>freeSwapKillThreshold</option>), SIGKILL is sent.
+
+        See <link xlink:href="https://github.com/rfjakob/earlyoom#command-line-options">README</link> for details.
+      '';
+    };
+
+    freeMemKillThreshold = mkOption {
+      type = types.nullOr (types.ints.between 1 100);
+      default = null;
+      description = ''
+        Minimum available memory (in percent) before sending SIGKILL.
+        If unset, this defaults to half of <option>freeMemThreshold</option>.
+
+        See the description of <xref linkend="opt-services.earlyoom.freeMemThreshold"/>.
+      '';
+    };
+
+    freeSwapThreshold = mkOption {
+      type = types.ints.between 1 100;
+      default = 10;
+      description = ''
+        Minimum free swap space (in percent) before sending SIGTERM.
+
+        See the description of <xref linkend="opt-services.earlyoom.freeMemThreshold"/>.
+      '';
+    };
+
+    freeSwapKillThreshold = mkOption {
+      type = types.nullOr (types.ints.between 1 100);
+      default = null;
+      description = ''
+        Minimum free swap space (in percent) before sending SIGKILL.
+        If unset, this defaults to half of <option>freeSwapThreshold</option>.
+
+        See the description of <xref linkend="opt-services.earlyoom.freeMemThreshold"/>.
+      '';
+    };
+
+    enableDebugInfo = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Enable debugging messages.
+      '';
+    };
+
+    enableNotifications = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Send notifications about killed processes via the system d-bus.
+
+        WARNING: enabling this option (while convenient) should *not* be done on a
+        machine where you do not trust the other users as it allows any other
+        local user to DoS your session by spamming notifications.
+
+        To actually see the notifications in your GUI session, you need to have
+        <literal>systembus-notify</literal> running as your user, which this
+        option handles by enabling <option>services.systembus-notify</option>.
+
+        See <link xlink:href="https://github.com/rfjakob/earlyoom#notifications">README</link> for details.
+      '';
+    };
+
+    killHook = mkOption {
+      type = types.nullOr types.path;
+      default = null;
+      example = literalExpression ''
+        pkgs.writeShellScript "earlyoom-kill-hook" '''
+          echo "Process $EARLYOOM_NAME ($EARLYOOM_PID) was killed" >> /path/to/log
+        '''
+      '';
+      description = ''
+        An absolute path to an executable to be run for each process killed.
+        Some environment variables are available, see
+        <link xlink:href="https://github.com/rfjakob/earlyoom#notifications">README</link> and
+        <link xlink:href="https://github.com/rfjakob/earlyoom/blob/master/MANPAGE.md#-n-pathtoscript">the man page</link>
+        for details.
+      '';
+    };
+
+    reportInterval = mkOption {
+      type = types.int;
+      default = 3600;
+      example = 0;
+      description = "Interval (in seconds) at which a memory report is printed (set to 0 to disable).";
+    };
+
+    extraArgs = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      example = [ "-g" "--prefer '(^|/)(java|chromium)$'" ];
+      description = "Extra command-line arguments to be passed to earlyoom.";
+    };
+  };
+
+  imports = [
+    (mkRemovedOptionModule [ "services" "earlyoom" "useKernelOOMKiller" ] ''
+      This option is deprecated and ignored by earlyoom since 1.2.
+    '')
+    (mkRemovedOptionModule [ "services" "earlyoom" "notificationsCommand" ] ''
+      This option was removed in earlyoom 1.6, but was reimplemented in 1.7
+      and is available as the new option `services.earlyoom.killHook`.
+    '')
+    (mkRemovedOptionModule [ "services" "earlyoom" "ignoreOOMScoreAdjust" ] ''
+      This option is deprecated and ignored by earlyoom since 1.7.
+    '')
+  ];
+
+  config = mkIf cfg.enable {
+    services.systembus-notify.enable = mkDefault cfg.enableNotifications;
+
+    systemd.services.earlyoom = {
+      description = "Early OOM Daemon for Linux";
+      wantedBy = [ "multi-user.target" ];
+      path = optional cfg.enableNotifications pkgs.dbus;
+      serviceConfig = {
+        StandardError = "journal";
+        ExecStart = concatStringsSep " " ([
+          "${pkgs.earlyoom}/bin/earlyoom"
+          ("-m ${toString cfg.freeMemThreshold}"
+            + optionalString (cfg.freeMemKillThreshold != null) ",${toString cfg.freeMemKillThreshold}")
+          ("-s ${toString cfg.freeSwapThreshold}"
+            + optionalString (cfg.freeSwapKillThreshold != null) ",${toString cfg.freeSwapKillThreshold}")
+          "-r ${toString cfg.reportInterval}"
+        ]
+        ++ optional cfg.enableDebugInfo "-d"
+        ++ optional cfg.enableNotifications "-n"
+        ++ optional (cfg.killHook != null) "-N ${escapeShellArg cfg.killHook}"
+        ++ cfg.extraArgs
+        );
+      };
+    };
+  };
+}