diff --git a/include/nitro/hw/common/mmap_shared.h b/include/nitro/hw/common/mmap_shared.h
index d8a5291..8b89add 100644
--- a/include/nitro/hw/common/mmap_shared.h
+++ b/include/nitro/hw/common/mmap_shared.h
@@ -206,6 +206,9 @@ extern "C" {
 // MEMORY MAP of SYSTEM SHARED AREA
 //----------------------------------------------------------------------
 //
+#define HW_TWL_ROM_HEADER_BUF           (HW_MAIN_MEM_EX_END - 0x2000)    // TWL-ROM内登録エリアデータ・バッファ
+#define HW_TWL_ROM_HEADER_BUF_END       (HW_MAIN_MEM_EX_END - 0x1000)
+
 #define HW_RED_RESERVED                 (HW_MAIN_MEM_EX_END - 0x800)      // maybe change later
 #define HW_RED_RESERVED_END             (HW_RED_RESERVED + HW_RED_RESERVED_SIZE)
 #define HW_RED_RESERVED_SIZE            0x200