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/virtualisation/amazon-options.nix

@@ -0,0 +1,74 @@
+{ config, lib, pkgs, ... }:
+let
+  inherit (lib) literalExpression types;
+in {
+  options = {
+    ec2 = {
+      zfs = {
+        enable = lib.mkOption {
+          default = false;
+          internal = true;
+          description = ''
+            Whether the EC2 instance uses a ZFS root.
+          '';
+        };
+
+        datasets = lib.mkOption {
+          description = ''
+            Datasets to create under the `tank` and `boot` zpools.
+
+            **NOTE:** This option is used only at image creation time, and
+            does not attempt to declaratively create or manage datasets
+            on an existing system.
+          '';
+
+          default = {};
+
+          type = types.attrsOf (types.submodule {
+            options = {
+              mount = lib.mkOption {
+                description = "Where to mount this dataset.";
+                type = types.nullOr types.string;
+                default = null;
+              };
+
+              properties = lib.mkOption {
+                description = "Properties to set on this dataset.";
+                type = types.attrsOf types.string;
+                default = {};
+              };
+            };
+          });
+        };
+      };
+      hvm = lib.mkOption {
+        default = lib.versionAtLeast config.system.stateVersion "17.03";
+        internal = true;
+        description = ''
+          Whether the EC2 instance is a HVM instance.
+        '';
+      };
+      efi = lib.mkOption {
+        default = pkgs.stdenv.hostPlatform.isAarch64;
+        defaultText = literalExpression "pkgs.stdenv.hostPlatform.isAarch64";
+        internal = true;
+        description = ''
+          Whether the EC2 instance is using EFI.
+        '';
+      };
+    };
+  };
+
+  config = lib.mkIf config.ec2.zfs.enable {
+    networking.hostId = lib.mkDefault "00000000";
+
+    fileSystems = let
+      mountable = lib.filterAttrs (_: value: ((value.mount or null) != null)) config.ec2.zfs.datasets;
+    in lib.mapAttrs'
+      (dataset: opts: lib.nameValuePair opts.mount {
+        device = dataset;
+        fsType = "zfs";
+      })
+      mountable;
+  };
+}