diff --git a/ChangeLog.txt b/ChangeLog.txt
index c6448b4bb..9b205521c 100755
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1398,4 +1398,6 @@
 
 	* apps/examples/can:  Extend the CAN loopback test by adding more
 	  command line options (2015-08-17).
+	* apps/examples/usbserial: Can now be run as an NSH builtin-function.
+	  Now uses a configurable IO buffer size (2015-08-20).
 
diff --git a/examples/usbserial/Kconfig b/examples/usbserial/Kconfig
index 1fd4e9b18..0ceea5d75 100644
--- a/examples/usbserial/Kconfig
+++ b/examples/usbserial/Kconfig
@@ -11,6 +11,13 @@ config EXAMPLES_USBSERIAL
 
 if EXAMPLES_USBSERIAL
 
+config EXAMPLES_USBSERIAL_BUFSIZE
+	int "Target I/O Buffer Size"
+	default 512
+	---help---
+		The size of the array that is used as an I/O buffer for USB serial
+		data transfers.
+
 config EXAMPLES_USBSERIAL_TRACEINIT
 	bool "USB Trace Initialization"
 	default n
diff --git a/examples/usbserial/Makefile b/examples/usbserial/Makefile
index 78dd4b1c7..f7d0b9602 100644
--- a/examples/usbserial/Makefile
+++ b/examples/usbserial/Makefile
@@ -37,6 +37,11 @@
 include $(APPDIR)/Make.defs
 
 # USB serial device example
+# Built-in application info
+
+APPNAME = usbserial
+PRIORITY = SCHED_PRIORITY_DEFAULT
+STACKSIZE = 2048
 
 ASRCS =
 CSRCS =
@@ -104,7 +109,14 @@ install:
 
 endif
 
+ifeq ($(CONFIG_NSH_BUILTIN_APPS),y)
+$(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat: $(DEPCONFIG) Makefile
+	$(call REGISTER,$(APPNAME),$(PRIORITY),$(STACKSIZE),$(APPNAME)_main)
+
+context: $(BUILTIN_REGISTRY)$(DELIM)$(APPNAME)_main.bdat
+else
 context:
+endif
 
 .depend: Makefile $(SRCS)
 	@$(MKDEP) $(ROOTDEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
diff --git a/examples/usbserial/Makefile.host b/examples/usbserial/Makefile.host
index 2dbaa7e92..c6ebf54e5 100644
--- a/examples/usbserial/Makefile.host
+++ b/examples/usbserial/Makefile.host
@@ -1,7 +1,7 @@
 ############################################################################
 # apps/examples/usbserial/Makefile.host
 #
-#   Copyright (C) 2008, 2011 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2008, 2011, 2015 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -53,6 +53,9 @@ endif
 ifeq ($(CONFIG_EXAMPLES_USBSERIAL_ONLYBIG),y)
 DEFINES	+= -DCONFIG_EXAMPLES_USBSERIAL_ONLYBIG=1
 endif
+ifeq ($(CONFIG_CDCACM),y)
+DEFINES	+= -DCONFIG_CDCACM=1
+endif
 
 all: $(BIN)
 
diff --git a/examples/usbserial/host.c b/examples/usbserial/host.c
index 37ff9efa8..1ccfce124 100644
--- a/examples/usbserial/host.c
+++ b/examples/usbserial/host.c
@@ -50,7 +50,7 @@
 #include <errno.h>
 
 /****************************************************************************
- * Definitions
+ * Pre-processor Definitions
  ****************************************************************************/
 
 #if defined(CONFIG_EXAMPLES_USBSERIAL_INONLY) && defined(CONFIG_EXAMPLES_USBSERIAL_OUTONLY)
@@ -181,6 +181,7 @@ int main(int argc, char **argv, char **envp)
           fprintf(stderr, "Too many arguments on command line\n");
           show_usage(argv[0], 1);
         }
+
       g_ttydev = argv[1];
     }
 
@@ -192,13 +193,15 @@ int main(int argc, char **argv, char **envp)
       fd = open(g_ttydev, O_RDWR);
       if (fd < 0)
         {
-          printf("main: ERROR: Failed to open %s: %s\n", g_ttydev, strerror(errno));
+          printf("main: ERROR: Failed to open %s: %s\n",
+                 g_ttydev, strerror(errno));
           printf("main:        Assume not connected. Wait and try again.\n");
           printf("main:        (Control-C to terminate).\n");
           sleep(5);
         }
     }
   while (fd < 0);
+
   printf("main: Successfully opened the serial driver\n");
 
   /* Configure the serial port in raw mode (at least turn off echo) */
@@ -206,7 +209,8 @@ int main(int argc, char **argv, char **envp)
   ret = tcgetattr(fd, &tty);
   if (ret < 0)
     {
-      printf("main: ERROR: Failed to get termios for %s: %s\n", g_ttydev, strerror(errno));
+      printf("main: ERROR: Failed to get termios for %s: %s\n",
+             g_ttydev, strerror(errno));
       close(fd);
       return 1;
     }
@@ -220,7 +224,8 @@ int main(int argc, char **argv, char **envp)
   ret = tcsetattr(fd, TCSANOW, &tty);
   if (ret < 0)
     {
-      printf("main: ERROR: Failed to set termios for %s: %s\n", g_ttydev, strerror(errno));
+      printf("main: ERROR: Failed to set termios for %s: %s\n",
+             g_ttydev, strerror(errno));
       close(fd);
       return 1;
     }
@@ -237,7 +242,8 @@ int main(int argc, char **argv, char **envp)
       nbytes = read(fd, g_iobuffer, BUFFER_SIZE-1);
       if (nbytes < 0)
         {
-          printf("main: ERROR: Failed to read from %s: %s\n", g_ttydev, strerror(errno));
+          printf("main: ERROR: Failed to read from %s: %s\n",
+                 g_ttydev, strerror(errno));
           close(fd);
           return 2;
         }
@@ -271,9 +277,11 @@ int main(int argc, char **argv, char **envp)
           nbytes = write(fd, g_longmsg, sizeof(g_longmsg));
           count = 0;
         }
+
 #elif !defined(CONFIG_EXAMPLES_USBSERIAL_ONLYSMALL)
       printf("main: Sending %d bytes..\n", sizeof(g_longmsg));
       nbytes = write(fd, g_longmsg, sizeof(g_longmsg));
+
 #else /* !defined(CONFIG_EXAMPLES_USBSERIAL_ONLYBIG) */
       printf("main: Sending %d bytes..\n", sizeof(g_shortmsg));
       nbytes = write(fd, g_shortmsg, sizeof(g_shortmsg));
@@ -287,6 +295,7 @@ int main(int argc, char **argv, char **envp)
           close(fd);
           return 2;
         }
+
       printf("main: %ld bytes sent\n", (long)nbytes);
 #endif /* CONFIG_EXAMPLES_USBSERIAL_INONLY */
     }
diff --git a/examples/usbserial/usbserial_main.c b/examples/usbserial/usbserial_main.c
index 13c4bdb5c..7a80d90e6 100644
--- a/examples/usbserial/usbserial_main.c
+++ b/examples/usbserial/usbserial_main.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * examples/usbserial/usbserial_main.c
  *
- *   Copyright (C) 2008, 2010-2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008, 2010-2012, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -56,7 +56,7 @@
 #endif
 
 /****************************************************************************
- * Definitions
+ * Pre-processor Definitions
  ****************************************************************************/
 
 #if defined(CONFIG_EXAMPLES_USBSERIAL_INONLY) && defined(CONFIG_EXAMPLES_USBSERIAL_OUTONLY)
@@ -113,7 +113,9 @@
 #  define USBSER_DEVNAME "/dev/ttyUSB0"
 #endif
 
-#define IOBUFFER_SIZE 256
+#ifndef CONFIG_EXAMPLES_USBSERIAL_BUFSIZE
+#  define CONFIG_EXAMPLES_USBSERIAL_BUFSIZE 256
+#endif
 
 /****************************************************************************
  * Private Data
@@ -153,7 +155,7 @@ static const char g_longmsg[] =
 #endif
 
 #ifndef CONFIG_EXAMPLES_USBSERIAL_INONLY
-static char g_iobuffer[IOBUFFER_SIZE];
+static char g_iobuffer[CONFIG_EXAMPLES_USBSERIAL_BUFSIZE];
 #endif
 
 /****************************************************************************
@@ -214,9 +216,11 @@ int usbserial_main(int argc, char *argv[])
 #endif
   if (ret < 0)
     {
-      printf("usbserial_main: ERROR: Failed to create the USB serial device: %d\n", -ret);
+      printf("usbserial_main: ERROR: Failed to create the USB serial device: %d\n",
+             -ret);
       return 1;
     }
+
   printf("usbserial_main: Successfully registered the serial driver\n");
 
 #if CONFIG_USBDEV_TRACE && CONFIG_USBDEV_TRACE_INITIALIDSET != 0
@@ -242,7 +246,8 @@ int usbserial_main(int argc, char *argv[])
       if (outfd < 0)
         {
           int errcode = errno;
-          printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME " for writing: %d\n", errcode);
+          printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME
+                 " for writing: %d\n", errcode);
 
           /* ENOTCONN means that the USB device is not yet connected */
 
@@ -274,7 +279,8 @@ int usbserial_main(int argc, char *argv[])
   infd = open(USBSER_DEVNAME, O_RDONLY|O_NONBLOCK);
   if (infd < 0)
     {
-      printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME " for reading: %d\n", errno);
+      printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME
+             " for reading: %d\n", errno);
       close(outfd);
       return 3;
     }
@@ -285,7 +291,8 @@ int usbserial_main(int argc, char *argv[])
       if (infd < 0)
         {
           int errcode = errno;
-          printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME " for reading: %d\n", errno);
+          printf("usbserial_main: ERROR: Failed to open " USBSER_DEVNAME
+                 " for reading: %d\n", errno);
 
           /* ENOTCONN means that the USB device is not yet connected */
 
@@ -333,9 +340,11 @@ int usbserial_main(int argc, char *argv[])
           nbytes = write(outfd, g_longmsg, sizeof(g_longmsg));
           count = 0;
         }
+
 #elif !defined(CONFIG_EXAMPLES_USBSERIAL_ONLYSMALL)
       printf("usbserial_main: Reciting QEI's speech of 1588\n");
       nbytes = write(outfd, g_longmsg, sizeof(g_longmsg));
+
 #else /* !defined(CONFIG_EXAMPLES_USBSERIAL_ONLYBIG) */
       printf("usbserial_main: Saying hello\n");
       nbytes = write(outfd, g_shortmsg, sizeof(g_shortmsg));
@@ -352,6 +361,7 @@ int usbserial_main(int argc, char *argv[])
           close(outfd);
           return 4;
         }
+
       printf("usbserial_main: %ld bytes sent\n", (long)nbytes);
 #endif /* CONFIG_EXAMPLES_USBSERIAL_OUTONLY */
 
@@ -363,8 +373,8 @@ int usbserial_main(int argc, char *argv[])
       printf("usbserial_main: Polling for OUT messages\n");
       for (i = 0; i < 5; i++)
         {
-          memset(g_iobuffer, 'X', IOBUFFER_SIZE);
-          nbytes = read(infd, g_iobuffer, IOBUFFER_SIZE);
+          memset(g_iobuffer, 'X', CONFIG_EXAMPLES_USBSERIAL_BUFSIZE);
+          nbytes = read(infd, g_iobuffer, CONFIG_EXAMPLES_USBSERIAL_BUFSIZE);
           if (nbytes < 0)
             {
               int errorcode = errno;
@@ -380,7 +390,7 @@ int usbserial_main(int argc, char *argv[])
             }
           else
             {
-              printf("usbserial_main: Received l%d bytes:\n", (long)nbytes);
+              printf("usbserial_main: Received %ld bytes:\n", (long)nbytes);
               if (nbytes > 0)
                 {
                   for (j = 0; j < nbytes; j += 16)
@@ -392,6 +402,7 @@ int usbserial_main(int argc, char *argv[])
                             {
                               printf(" ");
                             }
+
                           if (j+k < nbytes)
                             {
                               printf("%02x", g_iobuffer[j+k]);
@@ -401,6 +412,7 @@ int usbserial_main(int argc, char *argv[])
                               printf("  ");
                             }
                         }
+
                       printf(" ");
                       for (k = 0; k < 16; k++)
                         {
@@ -408,6 +420,7 @@ int usbserial_main(int argc, char *argv[])
                             {
                               printf(" ");
                             }
+
                           if (j+k < nbytes)
                             {
                               if (g_iobuffer[j+k] >= 0x20 && g_iobuffer[j+k] < 0x7f)
@@ -424,12 +437,15 @@ int usbserial_main(int argc, char *argv[])
                               printf(" ");
                             }
                         }
+
                       printf("\n");
                     }
                 }
             }
+
           sleep(1);
         }
+
 #else /* CONFIG_EXAMPLES_USBSERIAL_INONLY */
       printf("usbserial_main: Waiting\n");
       sleep(5);
@@ -450,4 +466,3 @@ int usbserial_main(int argc, char *argv[])
 #endif
   return 0;
 }
-