diff --git a/kern/efi/init.c b/kern/efi/init.c
index afd21055d..b79084a6a 100644
--- a/kern/efi/init.c
+++ b/kern/efi/init.c
@@ -24,6 +24,7 @@
 #include <grub/misc.h>
 #include <grub/env.h>
 #include <grub/mm.h>
+#include <grub/kernel.h>
 
 void
 grub_efi_init (void)
@@ -41,39 +42,58 @@ grub_efi_init (void)
 void
 grub_efi_set_prefix (void)
 {
-  grub_efi_loaded_image_t *image;
+  grub_efi_loaded_image_t *image = NULL;
+  char *device = NULL;
+  char *path = NULL;
 
-  image = grub_efi_get_loaded_image (grub_efi_image_handle);
-  if (image)
+  {
+    char *pptr = NULL;
+    if (grub_prefix[0] == '(')
+      {
+	pptr = grub_strrchr (grub_prefix, ')');
+	if (pptr)
+	  {
+	    device = grub_strndup (grub_prefix + 1, pptr - grub_prefix - 1);
+	    pptr++;
+	  }
+      }
+    if (!pptr)
+      pptr = grub_prefix;
+    if (pptr[0])
+      path = grub_strdup (pptr);
+  }
+
+  if (!device || !path)
+    image = grub_efi_get_loaded_image (grub_efi_image_handle);
+  if (image && !device)
+    device = grub_efidisk_get_device_name (image->device_handle);
+
+  if (image && !path)
     {
-      char *device;
-      char *file;
+      char *p;
 
-      device = grub_efidisk_get_device_name (image->device_handle);
-      file = grub_efi_get_filename (image->file_path);
+      path = grub_efi_get_filename (image->file_path);
 
-      if (device && file)
-	{
-	  char *p;
-	  char *prefix;
-
-	  /* Get the directory.  */
-	  p = grub_strrchr (file, '/');
-	  if (p)
-	    *p = '\0';
-
-	  prefix = grub_xasprintf ("(%s)%s", device, file);
-	  if (prefix)
-	    {
-	      
-	      grub_env_set ("prefix", prefix);
-	      grub_free (prefix);
-	    }
-	}
-
-      grub_free (device);
-      grub_free (file);
+      /* Get the directory.  */
+      p = grub_strrchr (path, '/');
+      if (p)
+	*p = '\0';
     }
+
+  if (device && path)
+    {
+      char *prefix;
+
+      prefix = grub_xasprintf ("(%s)%s", device, path);
+      if (prefix)
+	{
+	  grub_env_set ("prefix", prefix);
+	  grub_free (prefix);
+	}
+    }
+
+  grub_free (device);
+  grub_free (path);
 }
 
 void
diff --git a/util/grub-mkrescue.in b/util/grub-mkrescue.in
index cf791d108..0265f9b81 100644
--- a/util/grub-mkrescue.in
+++ b/util/grub-mkrescue.in
@@ -150,14 +150,16 @@ else
     esac
 fi
 
+# obtain date-based UUID
+iso_uuid=$(date -u +%Y-%m-%d-%H-%M-%S-00)
+grub_mkisofs_arguments="${grub_mkisofs_arguments} --modification-date=$(echo ${iso_uuid} | sed -e s/-//g)"
+
 # build coreboot core.img
 if test -e "${coreboot_dir}" ; then
     echo "Enabling coreboot support ..."
     memdisk_img=`mktemp "$MKTEMP_TEMPLATE"`
     memdisk_dir=`mktemp -d "$MKTEMP_TEMPLATE"`
     mkdir -p ${memdisk_dir}/boot/grub
-    # obtain date-based UUID
-    iso_uuid=$(date -u +%Y-%m-%d-%H-%M-%S-00)
 
     modules="$(cat ${coreboot_dir}/partmap.lst) ${modules}"
     cat << EOF > ${memdisk_dir}/boot/grub/grub.cfg
@@ -176,7 +178,6 @@ EOF
         memdisk tar search iso9660 configfile sh \
         ata at_keyboard
     rm -f ${memdisk_img}
-    grub_mkisofs_arguments="${grub_mkisofs_arguments} --modification-date=$(echo ${iso_uuid} | sed -e s/-//g)"
 fi
 
 # build BIOS core.img
@@ -213,8 +214,21 @@ fi
 # build bootx64.efi
 if test -e "${efi64_dir}" ; then
     echo "Enabling EFI64 support ..."
-    grub-mkimage -O x86_64-efi -d "${efi64_dir}" -o "${efi_dir}"/efi/boot/bootx64.efi --prefix=/boot/grub/x86_64-efi \
-        search iso9660 configfile sh 
+    memdisk_img=`mktemp "$MKTEMP_TEMPLATE"`
+    memdisk_dir=`mktemp -d "$MKTEMP_TEMPLATE"`
+    mkdir -p ${memdisk_dir}/boot/grub
+
+    cat << EOF > ${memdisk_dir}/boot/grub/grub.cfg
+search --fs-uuid --set ${iso_uuid}
+set prefix=(\${root})/boot/grub/${target_cpu}-efi
+EOF
+
+    tar -C ${memdisk_dir} -cf ${memdisk_img} boot
+    rm -rf ${memdisk_dir}
+
+    grub-mkimage -O x86_64-efi -d "${efi64_dir}" -m "${memdisk_img}" -o "${efi_dir}"/efi/boot/bootx64.efi --prefix='(memdisk)/boot/grub' \
+        search iso9660 configfile sh memdisk tar
+    rm -f ${memdisk_img}
 
     modules="$(cat "${efi64_dir}"/partmap.lst) ${modules}"
     (for i in ${modules} ; do