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/misc/xmr-stak.nix

@@ -0,0 +1,93 @@
+{ lib, config, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.xmr-stak;
+
+  pkg = pkgs.xmr-stak.override {
+    inherit (cfg) openclSupport cudaSupport;
+  };
+
+in
+
+{
+  options = {
+    services.xmr-stak = {
+      enable = mkEnableOption "xmr-stak miner";
+      openclSupport = mkEnableOption "support for OpenCL (AMD/ATI graphics cards)";
+      cudaSupport = mkEnableOption "support for CUDA (NVidia graphics cards)";
+
+      extraArgs = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        example = [ "--noCPU" "--currency monero" ];
+        description = "List of parameters to pass to xmr-stak.";
+      };
+
+      configFiles = mkOption {
+        type = types.attrsOf types.str;
+        default = {};
+        example = literalExpression ''
+          {
+            "config.txt" = '''
+              "verbose_level" : 4,
+              "h_print_time" : 60,
+              "tls_secure_algo" : true,
+            ''';
+            "pools.txt" = '''
+              "currency" : "monero7",
+              "pool_list" :
+              [ { "pool_address" : "pool.supportxmr.com:443",
+                  "wallet_address" : "my-wallet-address",
+                  "rig_id" : "",
+                  "pool_password" : "nixos",
+                  "use_nicehash" : false,
+                  "use_tls" : true,
+                  "tls_fingerprint" : "",
+                  "pool_weight" : 23
+                },
+              ],
+            ''';
+          }
+        '';
+        description = ''
+          Content of config files like config.txt, pools.txt or cpu.txt.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.xmr-stak = {
+      wantedBy = [ "multi-user.target" ];
+      bindsTo = [ "network-online.target" ];
+      after = [ "network-online.target" ];
+      environment = mkIf cfg.cudaSupport {
+        LD_LIBRARY_PATH = "${pkgs.linuxPackages_latest.nvidia_x11}/lib";
+      };
+
+      preStart = concatStrings (flip mapAttrsToList cfg.configFiles (fn: content: ''
+        ln -sf '${pkgs.writeText "xmr-stak-${fn}" content}' '${fn}'
+      ''));
+
+      serviceConfig = let rootRequired = cfg.openclSupport || cfg.cudaSupport; in {
+        ExecStart = "${pkg}/bin/xmr-stak ${concatStringsSep " " cfg.extraArgs}";
+        # xmr-stak generates cpu and/or gpu configuration files
+        WorkingDirectory = "/tmp";
+        PrivateTmp = true;
+        DynamicUser = !rootRequired;
+        LimitMEMLOCK = toString (1024*1024);
+      };
+    };
+  };
+
+  imports = [
+    (mkRemovedOptionModule ["services" "xmr-stak" "configText"] ''
+      This option was removed in favour of `services.xmr-stak.configFiles`
+      because the new config file `pools.txt` was introduced. You are
+      now able to define all other config files like cpu.txt or amd.txt.
+    '')
+  ];
+}