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/tests/nfs/simple.nix

@@ -0,0 +1,94 @@
+import ../make-test-python.nix ({ pkgs, version ? 4, ... }:
+
+let
+
+  client =
+    { pkgs, ... }:
+    { virtualisation.fileSystems =
+        { "/data" =
+           { # nfs4 exports the export with fsid=0 as a virtual root directory
+             device = if (version == 4) then "server:/" else "server:/data";
+             fsType = "nfs";
+             options = [ "vers=${toString version}" ];
+           };
+        };
+      networking.firewall.enable = false; # FIXME: only open statd
+    };
+
+in
+
+{
+  name = "nfs";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ eelco ];
+  };
+
+  nodes =
+    { client1 = client;
+      client2 = client;
+
+      server =
+        { ... }:
+        { services.nfs.server.enable = true;
+          services.nfs.server.exports =
+            ''
+              /data 192.168.1.0/255.255.255.0(rw,no_root_squash,no_subtree_check,fsid=0)
+            '';
+          services.nfs.server.createMountPoints = true;
+          networking.firewall.enable = false; # FIXME: figure out what ports need to be allowed
+        };
+    };
+
+  testScript =
+    ''
+      import time
+
+      server.wait_for_unit("nfs-server")
+      server.succeed("systemctl start network-online.target")
+      server.wait_for_unit("network-online.target")
+
+      start_all()
+
+      client1.wait_for_unit("data.mount")
+      client1.succeed("echo bla > /data/foo")
+      server.succeed("test -e /data/foo")
+
+      client2.wait_for_unit("data.mount")
+      client2.succeed("echo bla > /data/bar")
+      server.succeed("test -e /data/bar")
+
+      with subtest("restarting 'nfs-server' works correctly"):
+          server.succeed("systemctl restart nfs-server")
+          # will take 90 seconds due to the NFS grace period
+          client2.succeed("echo bla >> /data/bar")
+
+      with subtest("can get a lock"):
+          client2.succeed("time flock -n -s /data/lock true")
+
+      with subtest("client 2 fails to acquire lock held by client 1"):
+          client1.succeed("flock -x /data/lock -c 'touch locked; sleep 100000' >&2 &")
+          client1.wait_for_file("locked")
+          client2.fail("flock -n -s /data/lock true")
+
+      with subtest("client 2 obtains lock after resetting client 1"):
+          client2.succeed(
+              "flock -x /data/lock -c 'echo acquired; touch locked; sleep 100000' >&2 &"
+          )
+          client1.crash()
+          client1.start()
+          client2.wait_for_file("locked")
+
+      with subtest("locks survive server reboot"):
+          client1.wait_for_unit("data.mount")
+          server.shutdown()
+          server.start()
+          client1.succeed("touch /data/xyzzy")
+          client1.fail("time flock -n -s /data/lock true")
+
+      with subtest("unmounting during shutdown happens quickly"):
+          t1 = time.monotonic()
+          client1.shutdown()
+          duration = time.monotonic() - t1
+          assert duration < 30, f"shutdown took too long ({duration} seconds)"
+    '';
+})