diff --git a/easyflash/plugins/types/struct2json/src/cJSON.c b/easyflash/plugins/types/struct2json/src/cJSON.c
index f7bed44..4e3e480 100644
--- a/easyflash/plugins/types/struct2json/src/cJSON.c
+++ b/easyflash/plugins/types/struct2json/src/cJSON.c
@@ -52,7 +52,7 @@ static char* cJSON_strdup(const char* str)
       char* copy;
 
       len = strlen(str) + 1;
-      if (!(copy = (char*)cJSON_malloc(len))) return 0;
+      if ((copy = (char*)cJSON_malloc(len)) == NULL) return 0;
       memcpy(copy,str,len);
       return copy;
 }
@@ -350,7 +350,7 @@ char *cJSON_PrintBuffered(cJSON *item,int prebuffer,int fmt)
 	p.length=prebuffer;
 	p.offset=0;
 	return print_value(item,0,fmt,&p);
-	return p.buffer;
+	//return p.buffer;
 }
 
 
@@ -421,7 +421,7 @@ static const char *parse_array(cJSON *item,const char *value)
 	while (*value==',')
 	{
 		cJSON *new_item;
-		if (!(new_item=cJSON_New_Item())) return 0; 	/* memory fail */
+		if ((new_item=cJSON_New_Item()) == NULL) return 0; 	/* memory fail */
 		child->next=new_item;new_item->prev=child;child=new_item;
 		value=skip(parse_value(child,skip(value+1)));
 		if (!value) return 0;	/* memory fail */
@@ -533,7 +533,7 @@ static const char *parse_object(cJSON *item,const char *value)
 	while (*value==',')
 	{
 		cJSON *new_item;
-		if (!(new_item=cJSON_New_Item()))	return 0; /* memory fail */
+		if ((new_item=cJSON_New_Item()) == NULL)	return 0; /* memory fail */
 		child->next=new_item;new_item->prev=child;child=new_item;
 		value=skip(parse_string(child,skip(value+1)));
 		if (!value) return 0;
diff --git a/easyflash/src/ef_log.c b/easyflash/src/ef_log.c
index d69affd..6d31d38 100644
--- a/easyflash/src/ef_log.c
+++ b/easyflash/src/ef_log.c
@@ -124,7 +124,7 @@ static SectorStatus get_sector_status(uint32_t addr) {
     uint32_t status_full_magic = 0, status_use_magic = 0;
 
     /* calculate the sector header address */
-    header_addr = addr / EF_ERASE_MIN_SIZE * EF_ERASE_MIN_SIZE;
+    header_addr = addr & (~(EF_ERASE_MIN_SIZE - 1));
 
     if (ef_port_read(header_addr, header_buf, sizeof(header_buf)) == EF_NO_ERR) {
         sector_header_magic = header_buf[SECTOR_HEADER_MAGIC_INDEX];
@@ -164,7 +164,7 @@ static EfErrCode write_sector_status(uint32_t addr, SectorStatus status) {
     uint32_t header, header_addr = 0;
 
     /* calculate the sector header address */
-    header_addr = addr / EF_ERASE_MIN_SIZE * EF_ERASE_MIN_SIZE;
+    header_addr = addr & (~(EF_ERASE_MIN_SIZE - 1));
 
     /* calculate the sector staus magic */
     switch (status) {