diff --git a/kernel/include/hos_defines.h b/kernel/include/hos_defines.h
index dbbfd83..5a3a23f 100644
--- a/kernel/include/hos_defines.h
+++ b/kernel/include/hos_defines.h
@@ -11,4 +11,13 @@
 
 #define CONSOLE_MEMORY          (HOS_KERNEL_OFFSET + 0xB8000)
 
+extern  u8_t    _code;
+extern  u8_t    _data;
+extern  u8_t    _bss;
+extern  u8_t    _end;
+
+#define KERNEL_PHYSICAL_ADDRESS ((&_code) - HOS_KERNEL_OFFSET)
+#define KERNEL_VIRTUAL_ADDRESS  (&_code)
+#define KERNEL_SIZE             ((&_end) - (&_code))
+
 #endif