diff --git a/easyflash/inc/easyflash.h b/easyflash/inc/easyflash.h
index dceefe8..d323835 100644
--- a/easyflash/inc/easyflash.h
+++ b/easyflash/inc/easyflash.h
@@ -67,7 +67,7 @@ if (!(EXPR))                                                                  \
     while (1);                                                                \
 }
 /* EasyFlash software version number */
-#define EF_SW_VERSION                "2.08.26"
+#define EF_SW_VERSION                "2.10.11"
 
 typedef struct _ef_env{
     char *key;
diff --git a/easyflash/src/ef_env.c b/easyflash/src/ef_env.c
index 568ad3d..e913a3e 100644
--- a/easyflash/src/ef_env.c
+++ b/easyflash/src/ef_env.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the EasyFlash Library.
  *
- * Copyright (c) 2014, Armink, <armink.ztl@gmail.com>
+ * Copyright (c) 2014-2016, Armink, <armink.ztl@gmail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -67,19 +67,19 @@ enum {
 /* default ENV set, must be initialized by user */
 static ef_env const *default_env_set = NULL;
 /* default ENV set size, must be initialized by user */
-static size_t default_env_set_size = NULL;
+static size_t default_env_set_size = 0;
 /* ENV ram cache */
 static uint32_t env_cache[ENV_USER_SETTING_SIZE / 4] = { 0 };
 /* ENV start address in flash */
-static uint32_t env_start_addr = NULL;
+static uint32_t env_start_addr = 0;
 /* ENV ram cache has changed when ENV created, deleted and changed value. */
 static bool env_cache_changed = false;
 
 #ifdef EF_ENV_USING_PFS_MODE
 /* current load ENV area address */
-static uint32_t cur_load_area_addr = NULL;
+static uint32_t cur_load_area_addr = 0;
 /* next save ENV area address */
-static uint32_t next_save_area_addr = NULL;
+static uint32_t next_save_area_addr = 0;
 #endif
 
 static uint32_t get_env_system_addr(void);
diff --git a/easyflash/src/ef_env_wl.c b/easyflash/src/ef_env_wl.c
index c4821e4..e1adf9d 100644
--- a/easyflash/src/ef_env_wl.c
+++ b/easyflash/src/ef_env_wl.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the EasyFlash Library.
  *
- * Copyright (c) 2015, Armink, <armink.ztl@gmail.com>
+ * Copyright (c) 2015-2016, Armink, <armink.ztl@gmail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -74,21 +74,21 @@ enum {
 /* default ENV set, must be initialized by user */
 static ef_env const *default_env_set = NULL;
 /* default ENV set size, must be initialized by user */
-static size_t default_env_set_size = NULL;
+static size_t default_env_set_size = 0;
 /* flash ENV data section size */
-static size_t env_data_section_size = NULL;
+static size_t env_data_section_size = 0;
 /* ENV ram cache */
 static uint32_t env_cache[ENV_USER_SETTING_SIZE / 4] = { 0 };
 /* ENV start address in flash */
-static uint32_t env_start_addr = NULL;
+static uint32_t env_start_addr = 0;
 /* current using data section address */
-static uint32_t cur_using_data_addr = NULL;
+static uint32_t cur_using_data_addr = 0;
 /* ENV ram cache has changed when ENV created, deleted and changed value. */
 static bool env_cache_changed = false;
 
 #ifdef EF_ENV_USING_PFS_MODE
 /* next save ENV area address */
-static uint32_t next_save_area_addr = NULL;
+static uint32_t next_save_area_addr = 0;
 #endif
 
 static uint32_t get_env_start_addr(void);
diff --git a/easyflash/src/ef_iap.c b/easyflash/src/ef_iap.c
index 010bd47..16d1fd6 100644
--- a/easyflash/src/ef_iap.c
+++ b/easyflash/src/ef_iap.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the EasyFlash Library.
  *
- * Copyright (c) 2015, Armink, <armink.ztl@gmail.com>
+ * Copyright (c) 2015-2016, Armink, <armink.ztl@gmail.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -31,7 +31,7 @@
 #ifdef EF_USING_IAP
 
 /* IAP section backup application section start address in flash */
-static uint32_t bak_app_start_addr = NULL;
+static uint32_t bak_app_start_addr = 0;
 
 static uint32_t get_bak_app_start_addr(void);