diff --git a/components/utilities/zmodem/rz.c b/components/utilities/zmodem/rz.c
index fe09f4c4a..3bac91a37 100644
--- a/components/utilities/zmodem/rz.c
+++ b/components/utilities/zmodem/rz.c
@@ -19,13 +19,13 @@
 
 
 void zr_start(char *path);
-static rt_err_t zrec_init(rt_uint8_t *rxbuf,struct zfile *zf);
+static rt_err_t zrec_init(rt_uint8_t *rxbuf, struct zfile *zf);
 static rt_err_t zrec_files(struct zfile *zf);
-static rt_err_t zwrite_file(rt_uint8_t *buf,rt_uint16_t size,struct zfile *zf);
-static rt_err_t zrec_file_data(rt_uint8_t *buf,struct zfile *zf);;
-static rt_err_t zrec_file(rt_uint8_t *rxbuf,struct zfile *zf);
-static rt_err_t zget_file_info(char *name,struct zfile *zf);
-static rt_err_t zwrite_file(rt_uint8_t *buf,rt_uint16_t size,struct zfile *zf);
+static rt_err_t zwrite_file(rt_uint8_t *buf, rt_uint16_t size, struct zfile *zf);
+static rt_err_t zrec_file_data(rt_uint8_t *buf, struct zfile *zf);;
+static rt_err_t zrec_file(rt_uint8_t *rxbuf, struct zfile *zf);
+static rt_err_t zget_file_info(char *name, struct zfile *zf);
+static rt_err_t zwrite_file(rt_uint8_t *buf, rt_uint16_t size, struct zfile *zf);
 static void zrec_ack_bibi(void);
 
 
@@ -87,7 +87,7 @@ void zr_start(char *path)
 }
 
 /* receiver init, wait for ack */
-static rt_err_t zrec_init(rt_uint8_t *rxbuf,struct zfile *zf)
+static rt_err_t zrec_init(rt_uint8_t *rxbuf, struct zfile *zf)
 {
     rt_uint8_t err_cnt = 0;
 	rt_err_t res = -RT_ERROR;
@@ -183,7 +183,7 @@ static rt_err_t zrec_files(struct zfile *zf)
 	}
 }
 /* receive file */
-static rt_err_t zrec_file(rt_uint8_t *rxbuf,struct zfile *zf)
+static rt_err_t zrec_file(rt_uint8_t *rxbuf, struct zfile *zf)
 {
 	rt_err_t res = - RT_ERROR;
 	rt_uint16_t err_cnt = 0;
@@ -248,7 +248,7 @@ again:
 }
 
 /* proccess file infomation */
-static rt_err_t zget_file_info(char *name,struct zfile *zf)
+static rt_err_t zget_file_info(char *name, struct zfile *zf)
 {
 	char *p;
 	char *full_path,*ptr;
@@ -299,7 +299,7 @@ static rt_err_t zget_file_info(char *name,struct zfile *zf)
     zf->fname = full_path;
 	p = strlen(name)+name+1;	   
 	sscanf((const char *)p, "%ld%lo%o", &zf->bytes_total,&zf->ctime,&zf->mode);
-#ifdef DFS_USING_WORKDIR
+#ifdef defined(RT_USING_DFS) && defined(DFS_USING_WORKDIR)
 	dfs_statfs(working_directory,&buf);
 	if (zf->bytes_total > (buf.f_blocks * buf.f_bfree))
 	{
@@ -324,7 +324,7 @@ static rt_err_t zget_file_info(char *name,struct zfile *zf)
 }
 
 /* receive file data,continously, no ack */
-static rt_err_t zrec_file_data(rt_uint8_t *buf,struct zfile *zf)
+static rt_err_t zrec_file_data(rt_uint8_t *buf, struct zfile *zf)
 {
     rt_err_t res = -RT_ERROR;
 
@@ -369,7 +369,7 @@ more_data:
 }
 
 /* write file */
-static rt_err_t zwrite_file(rt_uint8_t *buf,rt_uint16_t size,struct zfile *zf)
+static rt_err_t zwrite_file(rt_uint8_t *buf,rt_uint16_t size, struct zfile *zf)
 {
 	return (write(zf->fd,buf,size));
 }
diff --git a/components/utilities/zmodem/sz.c b/components/utilities/zmodem/sz.c
index 4109f1060..ad30c9736 100644
--- a/components/utilities/zmodem/sz.c
+++ b/components/utilities/zmodem/sz.c
@@ -25,9 +25,9 @@ static rt_uint8_t ZF2_OP;		                  	 /* file transfer option */
 void zs_start(char *path);
 static void zsend_init(void);
 static rt_err_t zsend_files(struct zfile *zf);
-static rt_err_t zsend_file(struct zfile *zf,rt_uint8_t *buf, rt_uint16_t len);
+static rt_err_t zsend_file(struct zfile *zf, rt_uint8_t *buf, rt_uint16_t len);
 static rt_err_t zsend_file_data(struct zfile *zf);
-static rt_uint16_t zfill_buffer(struct zfile *zf,rt_uint8_t *buf,rt_uint16_t size);
+static rt_uint16_t zfill_buffer(struct zfile *zf, rt_uint8_t *buf, rt_uint16_t size);
 static rt_err_t zget_sync(void);
 static void zsay_bibi(void);
 
@@ -162,7 +162,7 @@ static rt_err_t zsend_files(struct zfile *zf)
 }
 
 /* send file name and related info */
-static rt_err_t zsend_file(struct zfile *zf,rt_uint8_t *buf, rt_uint16_t len)
+static rt_err_t zsend_file(struct zfile *zf, rt_uint8_t *buf, rt_uint16_t len)
 {
 	rt_uint8_t cnt;
 	rt_err_t res = -RT_ERROR;
@@ -262,7 +262,7 @@ get_syn1:
 }
 
 /* fill file data to buffer*/
-static rt_uint16_t zfill_buffer(struct zfile *zf,rt_uint8_t *buf,rt_uint16_t size)
+static rt_uint16_t zfill_buffer(struct zfile *zf, rt_uint8_t *buf, rt_uint16_t size)
 {
 	return (read(zf->fd,buf,size));
 }
diff --git a/components/utilities/zmodem/zcore.c b/components/utilities/zmodem/zcore.c
index 98406727a..cd52e2b24 100644
--- a/components/utilities/zmodem/zcore.c
+++ b/components/utilities/zmodem/zcore.c
@@ -37,8 +37,8 @@ void zinit_parameter(void);
 void zsend_bin_header(rt_uint8_t type, rt_uint8_t *hdr);
 void zsend_hex_header(rt_uint8_t type, rt_uint8_t *hdr);
 void zsend_bin_data(rt_uint8_t *buf, rt_int16_t len, rt_uint8_t frameend);
-static rt_int16_t zrec_data16(rt_uint8_t *buf,rt_uint16_t len);
-static rt_int16_t zrec_data32(rt_uint8_t *buf,rt_int16_t len);
+static rt_int16_t zrec_data16(rt_uint8_t *buf, rt_uint16_t len);
+static rt_int16_t zrec_data32(rt_uint8_t *buf, rt_int16_t len);
 static rt_int16_t zrec_data32r(rt_uint8_t *buf, rt_int16_t len);
 rt_int16_t zget_data(rt_uint8_t *buf, rt_uint16_t len);
 rt_int16_t zget_header(rt_uint8_t *hdr);
@@ -271,17 +271,16 @@ void zsend_bin_data(rt_uint8_t *buf, rt_int16_t len, rt_uint8_t frameend)
 }
 
 /* receive data,with 16bits CRC check */
-static rt_int16_t zrec_data16(rt_uint8_t *buf,rt_uint16_t len)
+static rt_int16_t zrec_data16(rt_uint8_t *buf, rt_uint16_t len)
 {
 	rt_int16_t c,crc_cnt;
 	rt_uint16_t crc;
 	rt_err_t res = -RT_ERROR;
  	rt_uint8_t *p,flag = 0;
-	rt_uint8_t i =0, debug[20];
-	p = buf;
-	crc = 0L;  
-    Rxcount = 0; 
-	debug[0] = debug[4] = 0; 
+
+	p = buf;	
+	crc_cnt = 0;  crc = 0L;   
+    Rxcount = 0; 
 	while(buf <= p+len) 
 	{
 		if ((res = zread_byte()) & ~0377)
@@ -290,8 +289,6 @@ static rt_int16_t zrec_data16(rt_uint8_t *buf,rt_uint16_t len)
 			    res == GOTCRCQ || res == GOTCRCW)
 			{
 				  c = res;
-				  debug[i++] = res;
-				  c = debug[0];
 				  c = res;
 				  crc = updcrc16(res&0377, crc);
 				  flag = 1;	
@@ -308,7 +305,6 @@ static rt_int16_t zrec_data16(rt_uint8_t *buf,rt_uint16_t len)
 		   {
 		       crc = updcrc16(res, crc); 
 			   crc_cnt++;
-			   debug[i++] = res;
 			   if (crc_cnt < 2) continue;
 			   if ((crc & 0xffff))
 			   {
@@ -332,14 +328,14 @@ static rt_int16_t zrec_data16(rt_uint8_t *buf,rt_uint16_t len)
 }
 
 /* receive data,with 32bits CRC check */
-static rt_int16_t zrec_data32(rt_uint8_t *buf,rt_int16_t len)
+static rt_int16_t zrec_data32(rt_uint8_t *buf, rt_int16_t len)
 {
-	rt_int16_t c,crc_cnt = 0;
+	rt_int16_t c,crc_cnt;
 	rt_uint32_t crc;
 	rt_err_t res = -RT_ERROR;
 	rt_uint8_t *p,flag = 0;
 
-	crc = 0xffffffffL;  
+	crc_cnt = 0;   crc = 0xffffffffL;  
 	Rxcount = 0;  
 	while (buf <= p+len) 
 	{
@@ -388,12 +384,12 @@ static rt_int16_t zrec_data32(rt_uint8_t *buf,rt_int16_t len)
 /* receive data,with RLE encoded,32bits CRC check */
 static rt_int16_t zrec_data32r(rt_uint8_t *buf, rt_int16_t len)
 {
-	rt_int16_t c,crc_cnt = 0;
+	rt_int16_t c,crc_cnt;
 	rt_uint32_t crc;
 	rt_err_t res = -RT_ERROR;
 	rt_uint8_t *p,flag = 0;
 
-	crc = 0xffffffffL;  
+	crc_cnt = 0; crc = 0xffffffffL;  
 	Rxcount = 0;  
 	p = buf;
 	while (buf <= p+len) 
@@ -640,7 +636,8 @@ static rt_int16_t zget_bin_fcs(rt_uint8_t *hdr)
 	if ((res = zread_byte()) & ~0377)
 		return res;
 	header_type = res;
-	crc = 0xFFFFFFFFL; crc = updcrc32(res, crc);
+	crc = 0xFFFFFFFFL; 
+	crc = updcrc32(res, crc);
 
 	for (i=0;i<4;i++)    /* 4headers */
 	{
@@ -859,8 +856,8 @@ rt_int16_t zxor_read(void)
 		default:
 			return res;
 		}
-	}
-	/* NOTREACHED */
+	}
+
 }
 
 /* put file posistion into the header*/
diff --git a/components/utilities/zmodem/zdevice.c b/components/utilities/zmodem/zdevice.c
index 794f01cae..6bf57d3b9 100644
--- a/components/utilities/zmodem/zdevice.c
+++ b/components/utilities/zmodem/zdevice.c
@@ -34,7 +34,7 @@ rt_uint32_t get_sys_time(void)
 
 void zsend_byte(rt_uint16_t ch)
 {
-    rt_device_write(zmodem.device,0,&ch,1);  
+    rt_device_write(zmodem.device, 0, &ch,1);  
 
     return;
 }
@@ -44,7 +44,7 @@ void zsend_line(rt_uint16_t c)
     rt_uint16_t ch;
 
 	ch = (c & 0377);
-    rt_device_write(zmodem.device,0,&ch,1);   
+    rt_device_write(zmodem.device, 0, &ch, 1);   
 
     return;
 }