diff --git a/test/boot-stage-1-init.sh b/test/boot-stage-1-init.sh
index a2e958d91f6..1299599a94e 100644
--- a/test/boot-stage-1-init.sh
+++ b/test/boot-stage-1-init.sh
@@ -6,11 +6,13 @@ fail() {
     exec @shell@
 }
 
+
 # Print a greeting.
 echo
 echo "<<< NixOS Stage 1 >>>"
 echo
 
+
 # Set the PATH.
 export PATH=/empty
 for i in @path@; do
@@ -20,6 +22,7 @@ for i in @path@; do
     fi
 done
 
+
 # Mount special file systems.
 mkdir /etc # to shut up mount
 touch /etc/fstab # idem
@@ -28,52 +31,68 @@ mount -t proc none /proc
 mkdir /sys
 mount -t sysfs none /sys
 
+
 # Create device nodes in /dev.
 source @makeDevices@
 
+
 # Load some kernel modules.
 export MODULE_DIR=@modules@/lib/modules/
 modprobe ide-generic
 modprobe ide-disk
 modprobe ide-cd
 
-# Try to find and mount the installation CD.
 
-# Mount the installation CD.
+# Try to find and mount the root device.
 mkdir /mnt
-mkdir /mnt/cdrom
+mkdir /mnt/root
 
-echo "probing for the NixOS installation CD..."
+echo "mounting the root device..."
 
-for i in /sys/devices/*/*/media; do
-    if test "$(cat $i)" = "cdrom"; then
+if test -n "@autoDetectRootDevice@"; then
 
-        # Hopefully `drivename' matches the device created in /dev.
-        devName=/dev/$(cat $(dirname $i)/drivename)
+    # Look for the root device by label.
+    echo "probing for the NixOS installation CD..."
 
-        echo "  in $devName..."
+    for i in /sys/devices/*/*/media; do
+        if test "$(cat $i)" = "cdrom"; then
 
-        if mount -o ro -t iso9660 $devName /mnt/cdrom; then
-            if test -e "/mnt/cdrom/@cdromLabel@"; then
-                found=1
-                break
+            # Hopefully `drivename' matches the device created in /dev.
+            devName=/dev/$(cat $(dirname $i)/drivename)
+
+            echo "  in $devName..."
+
+            if mount -o ro -t iso9660 $devName /mnt/root; then
+                if test -e "/mnt/root/@rootLabel@"; then
+                    found=1
+                    break
+                fi
+                umount /mnt/root
             fi
-            umount /mnt/cdrom
-        fi
         
-    fi
-done
+        fi
+    done
 
-if test -z "$found"; then
-    echo "CD not found!"
+    if test -z "$found"; then
+        echo "CD not found!"
+        fail
+    fi
+
+else
+
+    # Hard-coded root device.
+    mount -o ro "@rootDevice@" /mnt/root
+
+    # Testing.
     fail
+
 fi
 
 # Start stage 2.
 # !!! Note: we can't use pivot_root here (the kernel gods have
 # decreed), but we could use run-init from klibc, which deletes all
 # files in the initramfs, remounts the target root on /, and chroots.
-cd /mnt/cdrom
+cd /mnt/root
 mount --move . /
 umount /proc # cleanup
 umount /sys
diff --git a/test/boot-stage-1.nix b/test/boot-stage-1.nix
index 0f714a6d599..bb52b3f8354 100644
--- a/test/boot-stage-1.nix
+++ b/test/boot-stage-1.nix
@@ -6,13 +6,25 @@
 
 { genericSubstituter, shell, staticTools
 , module_init_tools, extraUtils, modules
-, cdromLabel ? ""
+
+, # Whether to find root device automatically using its label.
+  autoDetectRootDevice
+  
+, # If not scanning, the root must be specified explicitly.
+  rootDevice
+
+  # If scanning, we need a disk label.
+, rootLabel
 }:
 
+assert !autoDetectRootDevice -> rootDevice != "";
+assert autoDetectRootDevice -> rootLabel != "";
+
 genericSubstituter {
   src = ./boot-stage-1-init.sh;
   isExecutable = true;
-  inherit shell modules cdromLabel;
+  inherit shell modules;
+  inherit autoDetectRootDevice rootDevice rootLabel;
   path = [
     staticTools
     module_init_tools
diff --git a/test/rescue-cd.nix b/test/rescue-cd.nix
new file mode 100644
index 00000000000..defeeb48ece
--- /dev/null
+++ b/test/rescue-cd.nix
@@ -0,0 +1,63 @@
+let
+
+  # The label used to identify the installation CD.
+  cdromLabel = "NIXOS";
+
+in
+
+  # Build boot scripts for the CD that find the CD-ROM automatically.
+  with import ./rescue-system.nix {
+    autoDetectRootDevice = true;
+    rootLabel = cdromLabel;
+  };
+
+  
+rec {
+
+
+  # Since the CD is read-only, the mount points must be on disk.
+  cdMountPoints = pkgs.stdenv.mkDerivation {
+    name = "mount-points";
+    builder = builtins.toFile "builder.sh" "
+      source $stdenv/setup
+      mkdir $out
+      cd $out
+      mkdir proc sys tmp etc dev var mnt nix nix/var
+      touch $out/${cdromLabel}
+    ";
+  };
+
+
+  # Create an ISO image containing the isolinux boot loader, the
+  # kernel, the initrd produced above, and the closure of the stage 2
+  # init.
+  rescueCD = import ./make-iso9660-image.nix {
+    inherit (pkgs) stdenv cdrtools;
+    isoName = "nixos.iso";
+    
+    contents = [
+      { source = pkgs.syslinux + "/lib/syslinux/isolinux.bin";
+        target = "isolinux/isolinux.bin";
+      }
+      { source = ./isolinux.cfg;
+        target = "isolinux/isolinux.cfg";
+      }
+      { source = pkgs.kernel + "/vmlinuz";
+        target = "isolinux/vmlinuz";
+      }
+      { source = initialRamdisk + "/initrd";
+        target = "isolinux/initrd";
+      }
+      { source = cdMountPoints;
+        target = "/";
+      }
+    ];
+
+    init = bootStage2;
+    
+    bootable = true;
+    bootImage = "isolinux/isolinux.bin";
+  };
+
+
+}
diff --git a/test/rescue-system.nix b/test/rescue-system.nix
index b435d10f57f..890e3cfdf82 100644
--- a/test/rescue-system.nix
+++ b/test/rescue-system.nix
@@ -1,4 +1,8 @@
-{system ? __currentSystem}:
+{ system ? __currentSystem
+, autoDetectRootDevice ? false
+, rootDevice ? ""
+, rootLabel ? ""
+}:
 
 rec {
 
@@ -20,10 +24,6 @@ rec {
   };
 
 
-  # The label used to identify the installation CD.
-  cdromLabel = "NIXOS";
-
-
   # Determine the set of modules that we need to mount the root FS.
   modulesClosure = import ./modules-closure.nix {
     inherit (pkgs) stdenv kernel module_init_tools;
@@ -49,7 +49,7 @@ rec {
     inherit (pkgs) genericSubstituter;
     inherit (pkgsDiet) module_init_tools;
     inherit extraUtils;
-    inherit cdromLabel;
+    inherit autoDetectRootDevice rootDevice rootLabel;
     modules = modulesClosure;
     shell = stdenvLinuxStuff.bootstrapTools.bash;
     staticTools = stdenvLinuxStuff.staticTools;
@@ -113,49 +113,4 @@ rec {
   };
 
 
-  # Since the CD is read-only, the mount points must be on disk.
-  cdMountPoints = pkgs.stdenv.mkDerivation {
-    name = "mount-points";
-    builder = builtins.toFile "builder.sh" "
-      source $stdenv/setup
-      mkdir $out
-      cd $out
-      mkdir proc sys tmp etc dev var mnt nix nix/var
-      touch $out/${cdromLabel}
-    ";
-  };
-
-
-  # Create an ISO image containing the isolinux boot loader, the
-  # kernel, the initrd produced above, and the closure of the stage 2
-  # init.
-  rescueCD = import ./make-iso9660-image.nix {
-    inherit (pkgs) stdenv cdrtools;
-    isoName = "nixos.iso";
-    
-    contents = [
-      { source = pkgs.syslinux + "/lib/syslinux/isolinux.bin";
-        target = "isolinux/isolinux.bin";
-      }
-      { source = ./isolinux.cfg;
-        target = "isolinux/isolinux.cfg";
-      }
-      { source = pkgs.kernel + "/vmlinuz";
-        target = "isolinux/vmlinuz";
-      }
-      { source = initialRamdisk + "/initrd";
-        target = "isolinux/initrd";
-      }
-      { source = cdMountPoints;
-        target = "/";
-      }
-    ];
-
-    init = bootStage2;
-    
-    bootable = true;
-    bootImage = "isolinux/isolinux.bin";
-  };
-
-
 }