diff --git a/system/readline/readline_common.c b/system/readline/readline_common.c
index 92a98c53837..21c9217ac66 100644
--- a/system/readline/readline_common.c
+++ b/system/readline/readline_common.c
@@ -144,6 +144,7 @@ static int count_builtin_matches(FAR char *buf, FAR int *matches, int namelen)
  *   vtbl   - vtbl used to access implementation specific interface
  *   buf     - The user allocated buffer to be filled.
  *   buflen  - the size of the buffer.
+ *   nch     - the number of characters.
  *
  * Returned Value:
  *   None.
@@ -152,7 +153,7 @@ static int count_builtin_matches(FAR char *buf, FAR int *matches, int namelen)
 
 #ifdef CONFIG_READLINE_TABCOMPLETION
 static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
-                           int *nch)
+                           int buflen, int *nch)
 {
   FAR const char *name = NULL;
   char tmp_name[CONFIG_TASK_NAME_SIZE + 1];
@@ -271,7 +272,7 @@ static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
 
               if (tmp_name[0] == '\0')
                 {
-                  strcpy(tmp_name, name);
+                  strncpy(tmp_name, name, sizeof(tmp_name) - 1);
                 }
 
               RL_PUTC(vtbl, ' ');
@@ -306,7 +307,7 @@ static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
 
               if (tmp_name[0] == '\0')
                 {
-                  strcpy(tmp_name, name);
+                  strncpy(tmp_name, name, sizeof(tmp_name) - 1);
                 }
 
               RL_PUTC(vtbl, ' ');
@@ -329,7 +330,7 @@ static void tab_completion(FAR struct rl_common_s *vtbl, char *buf,
               RL_PUTC(vtbl, '\n');
             }
 #endif
-          strcpy(buf, tmp_name);
+          strncpy(buf, tmp_name, buflen - 1);
 
           name_len = strlen(tmp_name);
 
@@ -729,7 +730,7 @@ ssize_t readline_common(FAR struct rl_common_s *vtbl, FAR char *buf, int buflen)
 #ifdef CONFIG_READLINE_TABCOMPLETION
      else if (ch == '\t') /* Nghia - TAB character */
         {
-          tab_completion(vtbl, buf, &nch);
+          tab_completion(vtbl, buf, buflen, &nch);
         }
 #endif
     }
diff --git a/system/zmodem/Kconfig b/system/zmodem/Kconfig
index 2841751046c..21caa36bc83 100644
--- a/system/zmodem/Kconfig
+++ b/system/zmodem/Kconfig
@@ -62,6 +62,15 @@ config SYSTEM_ZMODEM_SNDBUFSIZE
 		The size of one transmit buffer used for composing messages sent to
 		the remote peer.
 
+config SYSTEM_ZMODEM_SNDFILEBUF
+	bool "Use cache buffer for file send"
+	default n
+	---help---
+		Read multiple bytes of file at once and store into a temporal buffer
+		which size is the same as SYSTEM_ZMODEM_SNDBUFSIZE. This is option
+		to improve the performance of file send, especially when the single
+		read of file is very slow.
+
 config SYSTEM_ZMODEM_MOUNTPOINT
 	string "Zmodem sandbox"
 	default "/tmp"
diff --git a/system/zmodem/Makefile.host b/system/zmodem/Makefile.host
index 968ae925d76..6e870eea8c6 100644
--- a/system/zmodem/Makefile.host
+++ b/system/zmodem/Makefile.host
@@ -43,7 +43,7 @@
 #        make -f Makefile.host TOPDIR=/home/me/projects/nuttx
 #          APPDIR=/home/me/projects/apps
 #
-#   2. Add CONFIG_DEBUG_FEATURES=1 to the make command line to enable debug output
+#   2. Add CONFIG_DEBUG_FEATURES=y to the make command line to enable debug output
 #   3. Make sure to clean old target .o files before making new host .o
 #      files.
 #
@@ -62,14 +62,14 @@ HOSTAPPS = $(ZMODEM)/host/apps
 HOSTCFLAGS  += -isystem $(HOSTDIR) -I $(ZMODEM) -I $(HOSTAPPS)
 HOSTCFLAGS  += -Dsz_main=main -Drz_main=main
 ifeq ($(CONFIG_DEBUG_FEATURES),y)
-HOSTCFLAGS  += -DCONFIG_DEBUG_ZMODEM=1 -DCONFIG_SYSTEM_ZMODEM_DUMPBUFFER=1
+HOSTCFLAGS  += -DCONFIG_DEBUG_ZMODEM=1
 endif
 
 # Zmodem sz and rz commands
 
 SZSRCS   = sz_main.c zm_send.c
 RZSRCS   = rz_main.c zm_receive.c
-CMNSRCS  = zm_state.c zm_proto.c zm_watchdog.c zm_utils.c zm_dumpbuffer.c
+CMNSRCS  = zm_state.c zm_proto.c zm_watchdog.c zm_utils.c
 CMNSRCS += crc16.c crc32.c
 SRCS     = $(SZSRCS) $(RZSRCS) $(CMNSRCS)
 
diff --git a/system/zmodem/zm.h b/system/zmodem/zm.h
index 6e888d0f493..d393b7780b3 100644
--- a/system/zmodem/zm.h
+++ b/system/zmodem/zm.h
@@ -49,6 +49,7 @@
 
 #include <stdint.h>
 #include <debug.h>
+#include <syslog.h>
 
 #include <nuttx/compiler.h>
 #include <nuttx/ascii.h>
@@ -357,6 +358,9 @@ struct zm_state_s
   uint8_t  rcvbuf[CONFIG_SYSTEM_ZMODEM_RCVBUFSIZE];
   uint8_t  pktbuf[ZM_PKTBUFSIZE];
   uint8_t  scratch[CONFIG_SYSTEM_ZMODEM_SNDBUFSIZE];
+#ifdef CONFIG_SYSTEM_ZMODEM_SNDFILEBUF
+  uint8_t  filebuf[CONFIG_SYSTEM_ZMODEM_SNDBUFSIZE];
+#endif
 };
 
 /* Receive state information */
diff --git a/system/zmodem/zm_send.c b/system/zmodem/zm_send.c
index 24fb60581ce..a12abe1ee54 100644
--- a/system/zmodem/zm_send.c
+++ b/system/zmodem/zm_send.c
@@ -872,7 +872,6 @@ static int zms_sendpacket(FAR struct zm_state_s *pzm)
   bool wait = false;
   int sndsize;
   int pktsize;
-  int ret;
   int i;
 
   /* Loop, sending packets while we can if the receiver supports streaming
@@ -977,12 +976,24 @@ static int zms_sendpacket(FAR struct zm_state_s *pzm)
       ptr         = pzm->scratch;
       pktsize     = 0;
 
+#ifdef CONFIG_SYSTEM_ZMODEM_SNDFILEBUF
+      /* Read multiple bytes of file and store into the temporal buffer */
+
+      zm_read(pzms->infd, pzm->filebuf, CONFIG_SYSTEM_ZMODEM_SNDBUFSIZE);
+
+      i = 0;
+#endif
+
       while (pktsize <= (CONFIG_SYSTEM_ZMODEM_SNDBUFSIZE - 10) &&
-             (ret = zm_getc(pzms->infd)) != EOF)
+             (pzms->offset < pzms->filesize))
         {
           /* Add the new value to the accumulated CRC */
 
-          uint8_t ch = (uint8_t)ret;
+#ifdef CONFIG_SYSTEM_ZMODEM_SNDFILEBUF
+          uint8_t ch = pzm->filebuf[i++];
+#else
+          uint8_t ch = zm_getc(pzms->infd);
+#endif
           if (!bcrc32)
             {
               crc = (uint32_t)crc16part(&ch, 1, (uint16_t)crc);
@@ -1007,6 +1018,12 @@ static int zms_sendpacket(FAR struct zm_state_s *pzm)
           pzms->offset++;
         }
 
+#ifdef CONFIG_SYSTEM_ZMODEM_SNDFILEBUF
+      /* Restore file position to be read next time */
+
+      lseek(pzms->infd, pzms->offset, SEEK_SET);
+#endif
+
       /* If we've reached file end, a ZEOF header will follow.  If there's
        * room in the outgoing buffer for it, end the packet with ZCRCE and
        * append the ZEOF header.  If there isn't room, we'll have to do a
@@ -1014,7 +1031,7 @@ static int zms_sendpacket(FAR struct zm_state_s *pzm)
        */
 
       pzm->flags &= ~ZM_FLAG_EOF;
-      if (ret == EOF)
+      if (pzms->offset == pzms->filesize)
         {
           pzm->flags |= ZM_FLAG_EOF;
           if (wait || (pzms->rcvmax != 0 && pktsize < 24))
diff --git a/system/zmodem/zm_state.c b/system/zmodem/zm_state.c
index 75844719ae8..a646bd371ad 100644
--- a/system/zmodem/zm_state.c
+++ b/system/zmodem/zm_state.c
@@ -755,7 +755,7 @@ static int zm_parse(FAR struct zm_state_s *pzm, size_t rcvlen)
   uint8_t ch;
   int ret;
 
-  DEBUGASSERT(pzm && rcvlen < CONFIG_SYSTEM_ZMODEM_RCVBUFSIZE);
+  DEBUGASSERT(pzm && rcvlen <= CONFIG_SYSTEM_ZMODEM_RCVBUFSIZE);
   zm_dumpbuffer("Received", pzm->rcvbuf, rcvlen);
 
   /* We keep a copy of the length and buffer index in the state structure.