nixos: move /eris/* in store image to /

All the ERIS URNs are prefixed already.

nixos-modules/eris/rom-vfs.dhall

@@ -18,7 +18,12 @@ in  λ(gptGuid : Text) →
             [ Init.Config.Policy::{
               , service = "File_system"
               , label = Init.LabelSelector.prefix "eris_rom"
-              , attributes = toMap { root = "/eris" }
+              , attributes = toMap { root = "/" }
+              }
+            , Init.Config.Policy::{
+              , service = "File_system"
+              , label = Init.LabelSelector.suffix "nix-store"
+              , attributes = toMap { root = "/nix/store" }
               }
             ]
           }

nixos-modules/genode-core.nix

@@ -77,11 +77,6 @@ let
               config.genode.core.romModules)))
           }] } ]'');
 
-    /* storeRomPolicies = mapAttrsToList
-          (name: value: '', { mapKey = "${name}", mapValue = "${value}" }'')
-          romDirectories;
-    */
-
     extraRoutes = lib.concatStringsSep ", " (lib.lists.flatten
       (lib.mapAttrsToList (name: value:
         map (suffix: ''
@@ -120,7 +115,7 @@ let
   '';
 
   erisContents = lib.attrsets.mapAttrsToList (urn: source: {
-    target = "eris/" + urn;
+    target = urn;
     inherit source;
   }) config.genode.init.romModules;
 
@@ -278,6 +273,10 @@ in {
         contents = erisContents;
         compressCommand = "cat";
         compressionExtension = "";
+        storeContents = lib.attrsets.mapAttrsToList (name: child: {
+          object = child.configFile;
+          symlink = "/config/${name}";
+        }) config.genode.init.children;
       };
 
     system.build.initXml = pkgs.buildPackages.runCommand "init.xml" {