diff --git a/boot/boot-stage-1.nix b/boot/boot-stage-1.nix
index edb8dab10da..fd87e5246d3 100644
--- a/boot/boot-stage-1.nix
+++ b/boot/boot-stage-1.nix
@@ -1,61 +1,129 @@
-# This Nix expression builds the script that performs the first stage
-# of booting the system: it loads the modules necessary to mount the
-# root file system, then calls /init in the root file system to start
-# the second boot stage.  The closure of the result of this expression
-# is supposed to be put into an initial RAM disk (initrd).
+# This Nix expression builds the initial ramdisk, which contains an
+# init script that performs the first stage of booting the system: it
+# loads the modules necessary to mount the root file system, then
+# calls the init in the root file system to start the second boot
+# stage.
 
-{ substituteAll, staticShell, klibcShrunk
-, extraUtils, modulesClosure
+{ pkgs, config, nixpkgsPath, kernelPackages, modulesTree }:
 
-, # Whether to find root device automatically using its label.
-  autoDetectRootDevice
+rec {
+
+  pkgsDiet = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix" {
+    system = pkgs.stdenv.system;
+    bootStdenv = pkgs.useDietLibC pkgs.stdenv;
+  };
+
+  pkgsStatic = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix" {
+    system = pkgs.stdenv.system;
+    bootStdenv = pkgs.makeStaticBinaries pkgs.stdenv;
+  };
+
+  stdenvLinuxStuff = import "${nixpkgsPath}/pkgs/stdenv/linux" {
+    system = pkgs.stdenv.system;
+    allPackages = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix";
+  };
   
-, # If not scanning, the root must be specified explicitly.  Actually,
-  # stage 1 can mount multiple file systems.  This is necessary if,
-  # for instance, /nix (necessary for stage 2) is on a different file
-  # system than /.
-  #
-  # This is a list of {mountPoint, device|label} attribute sets, i.e.,
-  # the format used by the fileSystems configuration option.  There
-  # must at least be a file system for the / mount point in this list.
-  fileSystems ? []
 
-, # If scanning, we need a disk label.
-  rootLabel
+  # Determine the set of modules that we need to mount the root FS.
+  modulesClosure = pkgs.makeModulesClosure {
+    rootModules =
+      config.boot.initrd.extraKernelModules ++
+      config.boot.initrd.kernelModules;
+    kernel = modulesTree;
+    allowMissing = config.boot.initrd.allowMissing;
+  };
 
-, # Whether the root device is read-only and should be made writable
-  # through a unionfs.
-  isLiveCD
 
-, # Resume device. [major]:[minor]
-  resumeDevice ? "ignore-this"
-}:
-
-let
-
-  # !!! use XML; copy&pasted from upstart-jobs/filesystems.nix.
-  mountPoints = map (fs: fs.mountPoint) fileSystems;
-  devices = map (fs: if fs ? device then fs.device else "LABEL=" + fs.label) fileSystems;
-  fsTypes = map (fs: if fs ? fsType then fs.fsType else "auto") fileSystems;
-  optionss = map (fs: if fs ? options then fs.options else "defaults") fileSystems;
-
-in
-
-if !autoDetectRootDevice && mountPoints == [] then abort "You must specify the fileSystems option!" else
-
-substituteAll {
-  src = ./boot-stage-1-init.sh;
+  # Some additional utilities needed in stage 1, notably mount.  We
+  # don't want to bring in all of util-linux, so we just copy what we
+  # need.
+  extraUtils = pkgs.runCommand "extra-utils"
+    { buildInputs = [pkgs.nukeReferences];
+      inherit (pkgsStatic) utillinux;
+      inherit (pkgsDiet) udev;
+      e2fsprogs = pkgs.e2fsprogsDiet;
+      devicemapper = if config.boot.initrd.lvm then pkgs.devicemapperStatic else null;
+      lvm2 = if config.boot.initrd.lvm then pkgs.lvm2Static else null;
+      allowedReferences = []; # prevent accidents like glibc being included in the initrd
+    }
+    ''
+      ensureDir $out/bin
+      if test -n "$devicemapper"; then
+        cp $devicemapper/sbin/dmsetup.static $out/bin/dmsetup
+        cp $lvm2/sbin/lvm.static $out/bin/lvm
+      fi
+      cp $utillinux/bin/mount $utillinux/bin/umount $utillinux/sbin/pivot_root $out/bin
+      cp -p $e2fsprogs/sbin/fsck* $e2fsprogs/sbin/e2fsck $out/bin
+      cp $udev/sbin/udevd $udev/sbin/udevadm $out/bin
+      nuke-refs $out/bin/*
+    ''; # */
   
-  isExecutable = true;
+
+  # The initrd only has to mount / or any FS marked as necessary for
+  # booting (such as the FS containing /nix/store, or an FS needed for
+  # mounting /, like / on a loopback).
+  fileSystems = pkgs.lib.filter
+    (fs: fs.mountPoint == "/" || (fs ? neededForBoot && fs.neededForBoot))
+    config.fileSystems;
+
+    
+  # The init script of boot stage 1 (loading kernel modules for
+  # mounting the root FS).
+  bootStage1 = pkgs.substituteAll {
+    src = ./boot-stage-1-init.sh;
+
+    isExecutable = true;
+
+    staticShell = stdenvLinuxStuff.bootstrapTools.bash;
+    
+    inherit modulesClosure;
+    
+    inherit (config.boot) autoDetectRootDevice isLiveCD resumeDevice;
+
+    # !!! copy&pasted from upstart-jobs/filesystems.nix.
+    mountPoints =
+      if !config.boot.autoDetectRootDevice && fileSystems == []
+      then abort "You must specify the fileSystems option!"
+      else map (fs: fs.mountPoint) fileSystems;
+    devices = map (fs: if fs ? device then fs.device else "LABEL=" + fs.label) fileSystems;
+    fsTypes = map (fs: if fs ? fsType then fs.fsType else "auto") fileSystems;
+    optionss = map (fs: if fs ? options then fs.options else "defaults") fileSystems;
+
+    rootLabel = if config.boot.autoDetectRootDevice then config.boot.rootLabel else "";
+
+    path = [
+      extraUtils
+      kernelPackages.klibcShrunk
+    ];
+  };
+
+
+  # The closure of the init script of boot stage 1 is what we put in
+  # the initial RAM disk.
+  initialRamdisk = pkgs.makeInitrd {
+    contents = [
+      { object = bootStage1;
+        symlink = "/init";
+      }
+    ] ++
+      pkgs.lib.optionals
+        (config.boot.initrd.enableSplashScreen && kernelPackages.splashutils != null)
+        [
+          { object = pkgs.runCommand "splashutils" {allowedReferences = []; buildInputs = [pkgs.nukeReferences];} ''
+              ensureDir $out/bin
+              cp ${kernelPackages.splashutils}/${kernelPackages.splashutils.helperName} $out/bin/splash_helper
+              nuke-refs $out/bin/*
+            '';
+            suffix = "/bin/splash_helper";
+            symlink = "/${kernelPackages.splashutils.helperName}";
+          } # */
+          { object = import ../helpers/unpack-theme.nix {
+              inherit (pkgs) stdenv;
+              theme = config.services.ttyBackgrounds.defaultTheme;
+            };
+            symlink = "/etc/splash";
+          }
+        ];
+  };
   
-  inherit staticShell modulesClosure;
-  
-  inherit autoDetectRootDevice isLiveCD mountPoints devices fsTypes optionss resumeDevice;
-  
-  rootLabel = if autoDetectRootDevice then rootLabel else "";
-  
-  path = [
-    extraUtils
-    klibcShrunk
-  ];
 }
diff --git a/system/system.nix b/system/system.nix
index b4c7078b4cd..3c4eb87e943 100644
--- a/system/system.nix
+++ b/system/system.nix
@@ -27,21 +27,6 @@ rec {
 
   pkgs = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix" {system = platform;};
 
-  pkgsDiet = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix" {
-    system = platform;
-    bootStdenv = pkgs.useDietLibC pkgs.stdenv;
-  };
-
-  pkgsStatic = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix" {
-    system = platform;
-    bootStdenv = pkgs.makeStaticBinaries pkgs.stdenv;
-  };
-
-  stdenvLinuxStuff = import "${nixpkgsPath}/pkgs/stdenv/linux" {
-    system = pkgs.stdenv.system;
-    allPackages = import "${nixpkgsPath}/pkgs/top-level/all-packages.nix";
-  };
-
   manifests = config.installer.manifests; # exported here because nixos-rebuild uses it
 
   nix = config.environment.nix pkgs;
@@ -50,11 +35,6 @@ rec {
 
   kernel = kernelPackages.kernel;
 
-  rootModules = 
-    config.boot.initrd.extraKernelModules ++
-    config.boot.initrd.kernelModules;
-
-
 
   # Tree of kernel modules.  This includes the kernel, plus modules
   # built outside of the kernel.  We have to combine these into a
@@ -69,84 +49,13 @@ rec {
     ++ config.boot.extraModulePackages pkgs
   );
 
-  
-  # Determine the set of modules that we need to mount the root FS.
-  modulesClosure = pkgs.makeModulesClosure {
-    inherit rootModules;
-    kernel = modulesTree;
-    allowMissing = config.boot.initrd.allowMissing;
+
+  # The initial ramdisk.
+  initialRamdiskStuff = import ../boot/boot-stage-1.nix {
+    inherit pkgs config nixpkgsPath kernelPackages modulesTree;
   };
 
-
-  # Some additional utilities needed in stage 1, notably mount.  We
-  # don't want to bring in all of util-linux, so we just copy what we
-  # need.
-  extraUtils = pkgs.runCommand "extra-utils"
-    { buildInputs = [pkgs.nukeReferences];
-      inherit (pkgsStatic) utillinux;
-      inherit (pkgsDiet) udev;
-      e2fsprogs = pkgs.e2fsprogsDiet;
-      devicemapper = if config.boot.initrd.lvm then pkgs.devicemapperStatic else null;
-      lvm2 = if config.boot.initrd.lvm then pkgs.lvm2Static else null;
-      allowedReferences = []; # prevent accidents like glibc being included in the initrd
-    }
-    ''
-      ensureDir $out/bin
-      if test -n "$devicemapper"; then
-        cp $devicemapper/sbin/dmsetup.static $out/bin/dmsetup
-        cp $lvm2/sbin/lvm.static $out/bin/lvm
-      fi
-      cp $utillinux/bin/mount $utillinux/bin/umount $utillinux/sbin/pivot_root $out/bin
-      cp -p $e2fsprogs/sbin/fsck* $e2fsprogs/sbin/e2fsck $out/bin
-      cp $udev/sbin/udevd $udev/sbin/udevadm $out/bin
-      nuke-refs $out/bin/*
-    ''; # */
-  
-
-  # The init script of boot stage 1 (loading kernel modules for
-  # mounting the root FS).
-  bootStage1 = import ../boot/boot-stage-1.nix {
-    inherit (pkgs) substituteAll;
-    inherit extraUtils modulesClosure;
-    inherit (kernelPackages) klibcShrunk;
-    inherit (config.boot) autoDetectRootDevice isLiveCD;
-    fileSystems =
-      pkgs.lib.filter
-        (fs: fs.mountPoint == "/" || (fs ? neededForBoot && fs.neededForBoot))
-        config.fileSystems;
-    rootLabel = config.boot.rootLabel;
-    staticShell = stdenvLinuxStuff.bootstrapTools.bash;
-    resumeDevice = config.boot.resumeDevice;
-  };
-  
-
-  # The closure of the init script of boot stage 1 is what we put in
-  # the initial RAM disk.
-  initialRamdisk = pkgs.makeInitrd {
-    contents = [
-      { object = bootStage1;
-        symlink = "/init";
-      }
-    ] ++
-      pkgs.lib.optionals
-        (config.boot.initrd.enableSplashScreen && kernelPackages.splashutils != null)
-        [
-          { object = pkgs.runCommand "splashutils" {allowedReferences = []; buildInputs = [pkgs.nukeReferences];} ''
-              ensureDir $out/bin
-              cp ${kernelPackages.splashutils}/${kernelPackages.splashutils.helperName} $out/bin/splash_helper
-              nuke-refs $out/bin/*
-            '';
-            suffix = "/bin/splash_helper";
-            symlink = "/${kernelPackages.splashutils.helperName}";
-          } # */
-          { object = import ../helpers/unpack-theme.nix {
-              inherit (pkgs) stdenv;
-              theme = config.services.ttyBackgrounds.defaultTheme;
-            };
-            symlink = "/etc/splash";
-          }
-        ];
-  };
+  initialRamdisk = initialRamdiskStuff.initialRamdisk;
 
 
   # NixOS installation/updating tools.