diff --git a/boot/boot-stage-1-init.sh b/boot/boot-stage-1-init.sh
index e3b26127d464..f1cad685e357 100644
--- a/boot/boot-stage-1-init.sh
+++ b/boot/boot-stage-1-init.sh
@@ -56,10 +56,10 @@ source @makeDevices@
 
 
 # Load some kernel modules.
-export MODULE_DIR=@modules@/lib/modules/
-modprobe ide-generic
-modprobe ide-disk
-modprobe ide-cd
+export MODULE_DIR=@modulesDir@/lib/modules/
+for i in @modules@; do
+    modprobe $i
+done
 
 
 # Try to find and mount the root device.
diff --git a/boot/boot-stage-1.nix b/boot/boot-stage-1.nix
index 63c562a13b9e..e33178f6881a 100644
--- a/boot/boot-stage-1.nix
+++ b/boot/boot-stage-1.nix
@@ -5,7 +5,7 @@
 # is supposed to be put into an initial RAM disk (initrd).
 
 { substituteAll, staticShell, staticTools
-, module_init_tools, extraUtils, modules
+, module_init_tools, extraUtils, modules, modulesDir
 
 , # Whether to find root device automatically using its label.
   autoDetectRootDevice
@@ -24,7 +24,7 @@
 substituteAll {
   src = ./boot-stage-1-init.sh;
   isExecutable = true;
-  inherit staticShell modules;
+  inherit staticShell modules modulesDir;
   inherit autoDetectRootDevice;
   rootDevice = if !autoDetectRootDevice then rootDevice else "";
   rootLabel = if autoDetectRootDevice then rootLabel else "";
diff --git a/configuration/options.nix b/configuration/options.nix
index 4ed40d97a1f3..cd7f2a929d88 100644
--- a/configuration/options.nix
+++ b/configuration/options.nix
@@ -93,6 +93,33 @@
   }
 
 
+  {
+    name = ["boot" "initrd" "kernelModules"];
+    default = ["ide-cd" "ide-disk" "ide-generic" "ext3"];
+    description = "
+      The set of kernel modules in the initial ramdisk used during the
+      boot process.  This set must include all modules necessary for
+      mounting the root device.  That is, it should include modules
+      for the physical device (e.g., SCSI drivers) and for the file
+      system (e.g., ext3).  The set specified here is automatically
+      closed under the module dependency relation, i.e., all
+      dependencies of the modules list here are included
+      automatically.  If you want to add additional
+      modules, it's best to set
+      <option>boot.initrd.extraKernelModules</options>.
+    ";
+  }
+
+
+  {
+    name = ["boot" "initrd" "extraKernelModules"];
+    default = [];
+    description = "
+      Additional kernel modules for the initial ramdisk.
+    ";
+  }
+
+
   {
     name = ["networking" "useDHCP"];
     default = true;
diff --git a/configuration/system.nix b/configuration/system.nix
index fddb0e4c41f7..133c12b935c2 100644
--- a/configuration/system.nix
+++ b/configuration/system.nix
@@ -36,10 +36,15 @@ rec {
   };
 
 
+  rootModules = 
+    (config.get ["boot" "initrd" "kernelModules"]) ++
+    (config.get ["boot" "initrd" "extraKernelModules"]);
+
+
   # Determine the set of modules that we need to mount the root FS.
   modulesClosure = import ../helpers/modules-closure.nix {
     inherit (pkgs) stdenv kernel module_init_tools;
-    rootModules = ["ide-cd" "ide-disk" "ide-generic"];
+    inherit rootModules;
   };
 
 
@@ -71,7 +76,8 @@ rec {
     rootDevice = config.get ["boot" "rootDevice"];
     rootLabel = config.get ["boot" "rootLabel"];
     inherit stage2Init;
-    modules = modulesClosure;
+    modulesDir = modulesClosure;
+    modules = rootModules;
     staticShell = stdenvLinuxStuff.bootstrapTools.bash;
     staticTools = stdenvLinuxStuff.staticTools;
   };