diff --git a/nixos-modules/eris/default.nix b/nixos-modules/eris/default.nix
index 53901e2..5233453 100644
--- a/nixos-modules/eris/default.nix
+++ b/nixos-modules/eris/default.nix
@@ -23,7 +23,7 @@
               ( VFS.vfs
                   [ VFS.leafAttrs
                       "plugin"
-                      (toMap { load = "${vfsRump.cap}", fs = "cd9660", ram = "12M", writeable="no" })
+                      (toMap { load = ${vfsRump.cap}, fs = "cd9660", ram = "12M", writeable="no" })
                   ]
               )
       '';
diff --git a/nixos-modules/genode-core.nix b/nixos-modules/genode-core.nix
index a20d1e1..e53d332 100644
--- a/nixos-modules/genode-core.nix
+++ b/nixos-modules/genode-core.nix
@@ -2,6 +2,8 @@
 
 with lib;
 let
+  toDhall = lib.generators.toDhall { };
+
   localPackages = pkgs.buildPackages;
 
   children' = config.lib.children.freeze
@@ -62,7 +64,7 @@ let
           '';
       };
 
-    manifest =
+    bootManifest =
       # Manifests are Dhall metadata to be attached to every
       # package to be used for dynamically buildings enviroments
       # using Dhall expressions. Probably not worth pursuing.
@@ -70,9 +72,9 @@ let
         (with pkgs.genodePackages; storeBackendInputs ++ coreInputs))
         + lib.optionalString (config.genode.core.romModules != { }) ''
           # [ { mapKey = "romModules", mapValue = [ ${
-            lib.concatStringsSep ", " (lib.lists.flatten ((map ({ name, value }:
-              ''{ mapKey = "${name}", mapValue = "${value}" }'')
-              config.genode.core.romModules)))
+            lib.concatStringsSep ", " (map
+              ({ name, value }: ''{ mapKey = ${name}, mapValue = "${value}" }'')
+              config.genode.core.romModules)
           }] } ]'');
 
     extraRoutes = lib.concatStringsSep ", " (lib.lists.flatten (let
@@ -105,12 +107,12 @@ let
     let XML = Sigil.Prelude.XML
     in
     ${./store-wrapper.dhall}
-    { binaries = { rtc_drv = "${rtc_drv.cap}" }
+    { binaries.rtc_drv = ${rtc_drv.cap}
     , extraCoreChildren = ${extraCoreChildren}
     , subinit = ${config.genode.init.configFile}
     , storeSize = $(stat --format '%s' ${tarball})
     , routes = [${extraRoutes} ] : List Sigil.Init.ServiceRoute.Type
-    , bootManifest = ${manifest}
+    , bootManifest = ${bootManifest}
     }
     EOF
   '';
@@ -236,11 +238,11 @@ in {
           value = path;
         }) (attrValues coreErisCaps)))) ++ [
           {
-            name = "init";
+            name = ''"init"'';
             value = "${pkgs.genodePackages.init}/bin/init";
           }
           {
-            name = "report_rom";
+            name = ''"report_rom"'';
             value = "${pkgs.genodePackages.report_rom}/bin/report_rom";
           }
         ];
@@ -271,18 +273,17 @@ in {
     system.build.configFile = bootConfigFile;
 
     # Create the tarball of the store to live in core ROM
-    system.build.tarball = pkgs.buildPackages.callPackage
-      "${modulesPath}/../lib/make-system-tarball.nix" {
-        extraInputs = lib.attrsets.mapAttrsToList (_: child: child.package)
-          config.genode.init.children;
-        contents = erisContents;
-        compressCommand = "cat";
-        compressionExtension = "";
-        storeContents = lib.attrsets.mapAttrsToList (name: child: {
-          object = child.configFile;
-          symlink = "/config/${name}";
-        }) config.genode.init.children;
-      };
+    system.build.tarball = localPackages.callPackage ./make-system-tarball.nix {
+      dhallContents = "[${
+          lib.concatStringsSep ","
+          (map ({ name, value }: ''{source = "${value}",target = ${name}}'')
+            config.genode.init.romModules)
+        }]";
+      storeContents = lib.attrsets.mapAttrsToList (name: child: {
+        object = child.configFile;
+        symlink = "/config/${name}";
+      }) config.genode.init.children;
+    };
 
     system.build.initXml = pkgs.buildPackages.runCommand "init.xml" {
       nativeBuildInputs = with pkgs.buildPackages; [ dhall xorg.lndir libxml2 ];
diff --git a/nixos-modules/hardware/default.nix b/nixos-modules/hardware/default.nix
index a6879ad..4439e3d 100644
--- a/nixos-modules/hardware/default.nix
+++ b/nixos-modules/hardware/default.nix
@@ -41,7 +41,7 @@ in {
       '';
 
     usbConfig = lib.optionalString cfg.usb.enable ''
-      , usb_block_drv = Some { binary = "${usbEris.usb_block_drv.cap}" }
+      , usb_block_drv = Some { binary = ${usbEris.usb_block_drv.cap} }
       , usb_host_drv = Some ${
         with cfg.usb.host;
         toDhall {
@@ -60,7 +60,7 @@ in {
 
       in  Manager.toChildAttributes
             Manager::{
-            , part_block.binary = "${partBlockEris.cap}"
+            , part_block.binary = ${partBlockEris.cap}
             ${ahciConfig}
             ${usbConfig}
             , verbose = ${toDhall cfg.verbose}
diff --git a/nixos-modules/lib/children.nix b/nixos-modules/lib/children.nix
index eacdcb7..4eb1943 100644
--- a/nixos-modules/lib/children.nix
+++ b/nixos-modules/lib/children.nix
@@ -77,8 +77,10 @@
             [{
               name = cap;
               value = path;
-            }] ++ (lib.mapAttrsToList (value: name: { inherit name value; })
-              closure);
+            }] ++ (lib.mapAttrsToList (name: value: {
+              name = ''"${value}"'';
+              value = name;
+            }) closure);
           extraRoms = map toRoms extraErisInputs;
         in if binary != null then {
           config = ''${configFile} "${binary}"'';
@@ -86,7 +88,7 @@
         } else
           let bin = lib.getErisMainProgram package;
           in {
-            config = ''${configFile} "${bin.cap}"'';
+            config = "${configFile} ${bin.cap}";
             roms = toRoms bin ++ extraRoms;
           }) children;
   };
diff --git a/nixos-modules/make-system-tarball.nix b/nixos-modules/make-system-tarball.nix
index 741e8fc..299e0da 100644
--- a/nixos-modules/make-system-tarball.nix
+++ b/nixos-modules/make-system-tarball.nix
@@ -1,40 +1,51 @@
-{ stdenv, closureInfo, dhall, dhall-bash
+{ stdenv, closureInfo, dhall-bash, dhallPackages, lndir
 
 , # The file name of the resulting tarball
-  fileName ? "nixos-system-${stdenv.hostPlatform.system}"
+fileName ? "nixos-system-${stdenv.hostPlatform.system}"
 
 , # The files and directories to be placed in the tarball.
-  # This is a list of attribute sets {source, target} where `source'
-  # is the file system object (regular file or directory) to be
-  # grafted in the file system at path `target'.
-  dhallContents
+# This is a Dhall list of attribute sets {source, target} where `source'
+# is the file system object (regular file or directory) to be
+# grafted in the file system at path `target'.
+dhallContents
 
 , # In addition to `contents', the closure of the store paths listed
-  # in `packages' are also placed in the Nix store of the tarball.  This is
-  # a list of attribute sets {object, symlink} where `object' if a
-  # store path whose closure will be copied, and `symlink' is a
-  # symlink to `object' that will be added to the tarball.
-  storeContents ? []
+# in `packages' are also placed in the Nix store of the tarball.  This is
+# a list of attribute sets {object, symlink} where `object' if a
+# store path whose closure will be copied, and `symlink' is a
+# symlink to `object' that will be added to the tarball.
+storeContents ? [ ]
 
   # Extra commands to be executed before archiving files
 , extraCommands ? ""
 
   # Extra tar arguments
-, extraArgs ? ""
-}:
+, extraArgs ? "" }:
 
 let
   symlinks = map (x: x.symlink) storeContents;
   objects = map (x: x.object) storeContents;
-in
 
-stdenv.mkDerivation {
+in stdenv.mkDerivation {
   name = "tarball";
   builder = ./make-system-tarball.sh;
-  nativeBuildInputs = [ dhall dhall-bash ];
+  nativeBuildInputs = [ dhall-bash lndir ];
 
   inherit fileName extraArgs dhallContents;
 
+  dhallPrelude = dhallPackages.Prelude;
+  # TODO: this should be done with a hook
+
+  extractContents = ''
+    let Prelude = ${dhallPackages.Prelude}/binary.dhall
+
+    let Mapping = { source : Text, target : Text }
+
+    let Mappings = List Mapping
+
+    in  \(f : Mapping -> Text) -> Prelude.List.map Mapping Text f env:dhallContents
+  '';
+
   # !!! should use XML.
   # sources = map (x: x.source) contents;
   # targets = map (x: x.target) contents;
@@ -42,7 +53,5 @@ stdenv.mkDerivation {
   # !!! should use XML.
   inherit symlinks objects;
 
-  closureInfo = closureInfo {
-    rootPaths = objects;
-  };
+  closureInfo = closureInfo { rootPaths = objects; };
 }
diff --git a/nixos-modules/make-system-tarball.sh b/nixos-modules/make-system-tarball.sh
index cf21425..50372d5 100644
--- a/nixos-modules/make-system-tarball.sh
+++ b/nixos-modules/make-system-tarball.sh
@@ -1,7 +1,16 @@
 source $stdenv/setup
 
-dhall <<< "env:dhallContents"
-exit 1
+# TODO: do this with a hook
+export XDG_CACHE_HOME=/tmp
+lndir -silent \
+  $dhallPrelude/.cache \
+  $XDG_CACHE_HOME
+
+eval $(dhall-to-bash --declare sources_ <<< "env:extractContents (λ(_: { source : Text, target : Text }) -> _.source)")
+eval $(dhall-to-bash --declare targets_ <<< "env:extractContents (λ(_: { source : Text, target : Text }) -> _.target)")
+
+echo $sources_
+echo $targets_
 
 objects=($objects)
 symlinks=($symlinks)
diff --git a/nixos-modules/nova.nix b/nixos-modules/nova.nix
index b8ba5ee..831dd9f 100644
--- a/nixos-modules/nova.nix
+++ b/nixos-modules/nova.nix
@@ -28,11 +28,11 @@ in {
 
   genode.core.romModules = [
     {
-      name = "ld.lib.so";
+      name = ''"ld.lib.so"'';
       value = "${pkgs.genodePackages.base-nova}/lib/ld.lib.so";
     }
     {
-      name = "timer_drv";
+      name = ''"timer_drv"'';
       value = "${pkgs.genodePackages.base-nova}/bin/timer_drv";
     }
   ];
diff --git a/packages/genodelabs/default.nix b/packages/genodelabs/default.nix
index e9eca5e..87a81c1 100644
--- a/packages/genodelabs/default.nix
+++ b/packages/genodelabs/default.nix
@@ -198,7 +198,10 @@ let
         runHook postInstall
       '';
 
-      meta = { platforms = lib.platforms.genode; } // meta;
+      meta = {
+        mainProgram = name;
+        platforms = lib.platforms.genode;
+      } // meta;
     });
 
   buildDepot =
@@ -289,7 +292,10 @@ let
         '';
 
         passthru = { inherit portInputs depotInputs; };
-        meta = { platforms = lib.platforms.genode; } // meta;
+        meta = {
+          mainProgram = name;
+          platforms = lib.platforms.genode;
+        } // meta;
       });
     in self;