diff --git a/Firmware/xflash_layout.h b/Firmware/xflash_layout.h
index 305846298..1e4a620c2 100644
--- a/Firmware/xflash_layout.h
+++ b/Firmware/xflash_layout.h
@@ -52,10 +52,14 @@
 #include "config.h"
 
 #define XFLASH_SIZE 0x40000ul // size of XFLASH
-#define LANG_OFFSET 0x0       // offset for language data
 
 #ifndef XFLASH_DUMP
-#define LANG_SIZE   XFLASH_SIZE
+#define MMU_BOOTLOADER_UPDATE_OFFSET (XFLASH_SIZE - 32768) // 32KB of MMU bootloader self update.
+#define MMU_FW_UPDATE_OFFSET (MMU_BOOTLOADER_UPDATE_OFFSET - 32768) // 32KB of MMU fw.
+#define LANG_OFFSET 0x0 // offset for language data
+
+#define LANG_SIZE (MMU_FW_UPDATE_OFFSET - LANG_OFFSET) // available language space
+
 #else
 
 #define DUMP_MAGIC  0x55525547ul
@@ -89,10 +93,12 @@ struct dump_t
     struct dump_data_t __attribute__((aligned(256))) data;
 };
 
-// dump offset must be aligned to lower 4kb sector boundary
-#define DUMP_OFFSET ((XFLASH_SIZE - sizeof(dump_t)) & ~0xFFFul)
+#define DUMP_OFFSET ((XFLASH_SIZE - sizeof(dump_t)) & ~0xFFFul) // dump offset must be aligned to lower 4kb sector boundary
+#define MMU_BOOTLOADER_UPDATE_OFFSET (DUMP_OFFSET - 32768) // 32KB of MMU bootloader self update.
+#define MMU_FW_UPDATE_OFFSET (MMU_BOOTLOADER_UPDATE_OFFSET - 32768) // 32KB of MMU fw.
+#define LANG_OFFSET 0x0 // offset for language data
 
-#define DUMP_SIZE   (XFLASH_SIZE - DUMP_OFFSET) // effective dump size area
-#define LANG_SIZE   DUMP_OFFSET                 // available language space
+#define LANG_SIZE (MMU_FW_UPDATE_OFFSET - LANG_OFFSET) // available language space
+#define DUMP_SIZE (XFLASH_SIZE - DUMP_OFFSET) // effective dump size area
 
 #endif