diff --git a/conf/i386-pc.rmk b/conf/i386-pc.rmk
index 37a9f5b..89ad861 100644
--- a/conf/i386-pc.rmk
+++ b/conf/i386-pc.rmk
@@ -155,7 +155,7 @@ pkglib_MODULES = biosdisk.mod _chain.mod _linux.mod linux.mod normal.mod \
 	vbe.mod vbetest.mod vbeinfo.mod video.mod gfxterm.mod \
 	videotest.mod play.mod bitmap.mod tga.mod cpuid.mod serial.mod	\
 	ata.mod vga.mod memdisk.mod jpeg.mod png.mod pci.mod lspci.mod \
-	aout.mod _bsd.mod bsd.mod
+	aout.mod _bsd.mod bsd.mod findroot.mod
 
 # For biosdisk.mod.
 biosdisk_mod_SOURCES = disk/i386/pc/biosdisk.c
@@ -322,4 +322,9 @@ bsd_mod_SOURCES = loader/i386/bsd_normal.c
 bsd_mod_CFLAGS = $(COMMON_CFLAGS)
 bsd_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+# For findroot.mod.
+findroot_mod_SOURCES = kern/findroot.c
+findroot_mod_CFLAGS = $(COMMON_CFLAGS)
+findroot_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 include $(srcdir)/conf/common.mk
diff --git a/include/grub/i386/pc/kernel.h b/include/grub/i386/pc/kernel.h
index 43a8d5b..c35b8d4 100644
--- a/include/grub/i386/pc/kernel.h
+++ b/include/grub/i386/pc/kernel.h
@@ -68,7 +68,7 @@ extern grub_int32_t grub_memdisk_image_size;
 
 /* The prefix which points to the directory where GRUB modules and its
    configuration file are located.  */
-extern char grub_prefix[];
+extern char EXPORT_VAR(grub_prefix) [];
 
 /* The boot BIOS drive number.  */
 extern grub_int32_t EXPORT_VAR(grub_boot_drive);
diff --git a/kern/findroot.c b/kern/findroot.c
new file mode 100755
index 0000000..6a6cc69
--- /dev/null
+++ b/kern/findroot.c
@@ -0,0 +1,77 @@
+/* findroot.c - search for root device */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/types.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/err.h>
+#include <grub/dl.h>
+#include <grub/device.h>
+#include <grub/file.h>
+#include <grub/env.h>
+#include <grub/machine/kernel.h>
+
+#define KERNEL_FILE	"/normal.mod"
+
+static void
+find_root (void)
+{
+  char *buf = 0;
+  auto int iterate_device (const char *name);
+
+  int iterate_device (const char *name)
+    {
+      grub_size_t len;
+      char *p;
+      grub_file_t file;
+
+      len = grub_strlen (name) + 2 + grub_strlen (grub_prefix) +
+            sizeof (KERNEL_FILE);
+
+      p = grub_realloc (buf, len);
+      if (! p)
+	return 1;
+
+      buf = p;
+      grub_sprintf (buf, "(%s)%s" KERNEL_FILE, name, grub_prefix);
+
+      file = grub_file_open (buf);
+      if (file)
+	{
+          buf[grub_strlen (name) + 2 + grub_strlen (grub_prefix)] = 0;
+          grub_env_set ("prefix", buf);
+
+          grub_file_close (file);
+
+          return 1;
+	}
+
+      grub_errno = GRUB_ERR_NONE;
+      return 0;
+    }
+
+  grub_device_iterate (iterate_device);
+
+  grub_free (buf);
+}
+
+GRUB_MOD_INIT(findroot)
+{
+  find_root ();
+}
diff --git a/kern/main.c b/kern/main.c
index 09de03a..a7e1e4f 100644
--- a/kern/main.c
+++ b/kern/main.c
@@ -124,7 +124,9 @@ grub_main (void)
 
   /* It is better to set the root device as soon as possible,
      for convenience.  */
-  grub_machine_set_prefix ();
+  if (! grub_env_get ("prefix"))
+    grub_machine_set_prefix ();
+
   grub_set_root_dev ();
 
   /* Load the normal mode module.  */