buildroot/boot/grub/grub.200-fix_mbr_handling.patch

Index: b/stage2/disk_io.c
===================================================================
--- a/stage2/disk_io.c
+++ b/stage2/disk_io.c
@@ -365,7 +365,7 @@
 int
 devwrite (unsigned int sector, int sector_count, char *buf)
 {
-#if defined(GRUB_UTIL) && defined(__linux__)
+#if defined(GRUB_UTIL) && defined(__linux__) && !defined(SUPPORT_LOOPDEV)
   if (current_partition != 0xFFFFFF
       && is_disk_device (device_map, current_drive))
     {