2009-06-08  Felix Zielcke  <address@hidden>

	    * include/grub/util/hostdisk.c
	    (grub_make_system_path_relative_to_its_root): New function
	    prototype.
	    * util/hostdisk.c (grub_make_system_path_relative_to_its_root):
	    New function.
	    * util/i386/pc/grub-setup.c (setup): Use
	    grub_make_system_path_relative_to_its_root to make core_path_dev
	    relative to the partition.

diff --git a/util/hostdisk.c b/util/hostdisk.c
index a7262dd..0a786ba 100644
--- a/util/hostdisk.c
+++ b/util/hostdisk.c
@@ -1076,3 +1076,39 @@ grub_util_biosdisk_get_grub_dev (const char *os_dev)
   return make_device_name (drive, -1, -1);
 #endif
 }
+
+char *grub_make_system_path_relative_to_its_root (char *path)
+{
+
+  struct stat st;
+  char buf[500], buf2[500];
+  dev_t num;
+  char *p;
+
+  if (stat (path, &st) < 0)
+    return NULL;
+
+  num = st.st_dev;
+  memset (buf, 0 , sizeof (buf));
+  strncpy (buf, path, 500);
+  strcpy (buf2, buf);
+  while (1)
+    {
+      p = strrchr (buf, '/');
+      if (p != buf)
+	*p = 0;
+      else *++p = 0;
+
+      if (stat (buf, &st) < 0)
+	return NULL;
+
+      if (st.st_dev != num)
+	break;
+      strcpy(buf2,buf);
+      if (p - 1 == buf)
+	return path;
+    }
+  for (p = buf2; *p != 0; p++)
+    path++;
+  return path;
+}
diff --git a/util/i386/pc/grub-setup.c b/util/i386/pc/grub-setup.c
index 997811b..9446fd5 100644
--- a/util/i386/pc/grub-setup.c
+++ b/util/i386/pc/grub-setup.c
@@ -405,6 +405,9 @@ unable_to_embed:
   /* Make sure that GRUB reads the identical image as the OS.  */
   tmp_img = xmalloc (core_size);
   core_path_dev = grub_util_get_path (dir, core_file);
+  core_path_dev = grub_make_system_path_relative_to_its_root (core_path_dev);
+  if (core_path_dev == NULL)
+    grub_util_error ("failed to make path of core.img relative to its root");
   
   /* It is a Good Thing to sync two times.  */
   sync ();