diff --git a/apps/Makefile b/apps/Makefile
index 19ad1c18bc..11d95bc190 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -112,6 +112,9 @@ endef
 
 $(foreach BUILTIN, $(CONFIGURED_APPS), $(eval $(call ADD_BUILTIN,$(BUILTIN))))
 
+# EXTERNAL_APPS is used to add out of tree apps to the build
+INSTALLED_APPS += $(EXTERNAL_APPS)
+
 # The external/ directory may also be added to the INSTALLED_APPS.  But there
 # is no external/ directory in the repository.  Rather, this directory may be
 # provided by the user (possibly as a symbolic link) to add libraries and
diff --git a/apps/drivers/drv_pwm_output.h b/apps/drivers/drv_pwm_output.h
index b2fee65aca..c110cd5cbc 100644
--- a/apps/drivers/drv_pwm_output.h
+++ b/apps/drivers/drv_pwm_output.h
@@ -103,6 +103,9 @@ ORB_DECLARE(output_pwm);
 /** disarm all servo outputs (stop generating pulses) */
 #define PWM_SERVO_DISARM	_IOC(_PWM_SERVO_BASE, 1)
 
+/** set update rate in Hz */
+#define PWM_SERVO_SET_UPDATE_RATE	_IOC(_PWM_SERVO_BASE, 2)
+
 /** set a single servo to a specific value */
 #define PWM_SERVO_SET(_servo)	_IOC(_PWM_SERVO_BASE, 0x20 + _servo)
 
diff --git a/apps/drivers/hil/hil.cpp b/apps/drivers/hil/hil.cpp
index af7598a34a..fe9b281f67 100644
--- a/apps/drivers/hil/hil.cpp
+++ b/apps/drivers/hil/hil.cpp
@@ -510,6 +510,10 @@ HIL::pwm_ioctl(file *filp, int cmd, unsigned long arg)
 		// up_pwm_servo_arm(false);
 		break;
 
+	case PWM_SERVO_SET_UPDATE_RATE:
+		g_hil->set_pwm_rate(arg);
+		break;
+
 	case PWM_SERVO_SET(2):
 	case PWM_SERVO_SET(3):
 		if (_mode != MODE_4PWM) {
diff --git a/apps/drivers/px4fmu/fmu.cpp b/apps/drivers/px4fmu/fmu.cpp
index ffe25b274a..430d18c6d5 100644
--- a/apps/drivers/px4fmu/fmu.cpp
+++ b/apps/drivers/px4fmu/fmu.cpp
@@ -509,6 +509,10 @@ PX4FMU::pwm_ioctl(file *filp, int cmd, unsigned long arg)
 		up_pwm_servo_arm(false);
 		break;
 
+	case PWM_SERVO_SET_UPDATE_RATE:
+		set_pwm_rate(arg);
+		break;
+
 	case PWM_SERVO_SET(2):
 	case PWM_SERVO_SET(3):
 		if (_mode != MODE_4PWM) {
diff --git a/apps/drivers/px4io/px4io.cpp b/apps/drivers/px4io/px4io.cpp
index 0c0b08343e..c2396b002c 100644
--- a/apps/drivers/px4io/px4io.cpp
+++ b/apps/drivers/px4io/px4io.cpp
@@ -709,6 +709,11 @@ PX4IO::ioctl(file *filep, int cmd, unsigned long arg)
 		_send_needed = true;
 		break;
 
+	case PWM_SERVO_SET_UPDATE_RATE:
+		// not supported yet
+		ret = -EINVAL;
+		break;
+
 	case PWM_SERVO_SET(0) ... PWM_SERVO_SET(_max_actuators - 1):
 
 		/* fake an update to the selected 'servo' channel */
diff --git a/apps/mavlink/mavlink_log.c b/apps/mavlink/mavlink_log.c
index 660e282f86..73d59e76fc 100644
--- a/apps/mavlink/mavlink_log.c
+++ b/apps/mavlink/mavlink_log.c
@@ -40,6 +40,7 @@
  */
 
 #include <string.h>
+#include <stdlib.h>
 
 #include "mavlink_log.h"
  
@@ -51,7 +52,7 @@ void mavlink_logbuffer_init(struct mavlink_logbuffer *lb, int size) {
 }
  
 int mavlink_logbuffer_is_full(struct mavlink_logbuffer *lb) {
-    return lb->count == lb->size;
+	return lb->count == (int)lb->size;
 }
  
 int mavlink_logbuffer_is_empty(struct mavlink_logbuffer *lb) {
@@ -77,4 +78,4 @@ int mavlink_logbuffer_read(struct mavlink_logbuffer *lb, struct mavlink_logmessa
     } else {
         return 1;
     }
-}
\ No newline at end of file
+}
diff --git a/apps/uORB/topics/vehicle_gps_position.h b/apps/uORB/topics/vehicle_gps_position.h
index ebd83e1a9b..db529da06d 100644
--- a/apps/uORB/topics/vehicle_gps_position.h
+++ b/apps/uORB/topics/vehicle_gps_position.h
@@ -65,8 +65,8 @@ struct vehicle_gps_position_s
 	uint16_t counter_pos_valid;		/**< is only increased when new lat/lon/alt information was added   */
 	uint16_t eph;				/**< GPS HDOP horizontal dilution of position in cm (m*100). If unknown, set to: 65535 //LOGME   */
 	uint16_t epv;				/**< GPS VDOP horizontal dilution of position in cm (m*100). If unknown, set to: 65535   */
-	float s_variance;			// XXX testing
-	float p_variance;			// XXX testing
+	float s_variance;			/**< speed accuracy estimate cm/s */
+	float p_variance;			/**< position accuracy estimate cm */
 	uint16_t vel;				/**< GPS ground speed (m/s * 100). If unknown, set to: 65535   */
 	float vel_n;				/**< GPS ground speed in m/s */
 	float vel_e;				/**< GPS ground speed in m/s */
@@ -84,7 +84,6 @@ struct vehicle_gps_position_s
 
 	/* flags */
 	float vel_ned_valid;			/**< Flag to indicate if NED speed is valid */
-
 };
 
 /**
diff --git a/nuttx/configs/px4fmu/nsh/defconfig b/nuttx/configs/px4fmu/nsh/defconfig
index d9a48f2c86..52013457e3 100755
--- a/nuttx/configs/px4fmu/nsh/defconfig
+++ b/nuttx/configs/px4fmu/nsh/defconfig
@@ -246,18 +246,18 @@ CONFIG_USART6_SERIAL_CONSOLE=n
 
 #Mavlink messages can be bigger than 128
 CONFIG_USART1_TXBUFSIZE=512
-CONFIG_USART2_TXBUFSIZE=128
-CONFIG_USART3_TXBUFSIZE=128
-CONFIG_UART4_TXBUFSIZE=128
-CONFIG_UART5_TXBUFSIZE=64
+CONFIG_USART2_TXBUFSIZE=256
+CONFIG_USART3_TXBUFSIZE=256
+CONFIG_UART4_TXBUFSIZE=256
+CONFIG_UART5_TXBUFSIZE=256
 CONFIG_USART6_TXBUFSIZE=128
 
 CONFIG_USART1_RXBUFSIZE=512
-CONFIG_USART2_RXBUFSIZE=128
-CONFIG_USART3_RXBUFSIZE=128
-CONFIG_UART4_RXBUFSIZE=128
-CONFIG_UART5_RXBUFSIZE=128
-CONFIG_USART6_RXBUFSIZE=128
+CONFIG_USART2_RXBUFSIZE=256
+CONFIG_USART3_RXBUFSIZE=256
+CONFIG_UART4_RXBUFSIZE=256
+CONFIG_UART5_RXBUFSIZE=256
+CONFIG_USART6_RXBUFSIZE=256
 
 CONFIG_USART1_BAUD=57600
 CONFIG_USART2_BAUD=115200
diff --git a/nuttx/drivers/serial/serial.c b/nuttx/drivers/serial/serial.c
index 28c657af05..da326f8c68 100644
--- a/nuttx/drivers/serial/serial.c
+++ b/nuttx/drivers/serial/serial.c
@@ -660,8 +660,10 @@ static int uart_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 
   int ret = dev->ops->ioctl(filep, cmd, arg);
 
-  /* If the low-level handler didn't handle the call, see if we can handle it here */
-
+  /*
+   * The device ioctl() handler returns -ENOTTY when it doesn't know
+   * how to handle the command. Check if we can handle it here.
+   */
   if (ret == -ENOTTY)
     {
       switch (cmd)
diff --git a/nuttx/include/stdio.h b/nuttx/include/stdio.h
index e9218046c5..754cedbb40 100644
--- a/nuttx/include/stdio.h
+++ b/nuttx/include/stdio.h
@@ -133,6 +133,7 @@ EXTERN void   perror(FAR const char *s);
 EXTERN int    ungetc(int c, FAR FILE *stream);
 EXTERN int    vprintf(FAR const char *format, va_list ap);
 EXTERN int    vfprintf(FAR FILE *stream, const char *format, va_list ap);
+EXTERN int    vdprintf(FAR int fd, const char *format, va_list ap);
 EXTERN int    vsprintf(FAR char *buf, const char *format, va_list ap);
 EXTERN int    avsprintf(FAR char **ptr, const char *fmt, va_list ap);
 EXTERN int    vsnprintf(FAR char *buf, size_t size, const char *format, va_list ap);
diff --git a/nuttx/lib/lib_internal.h b/nuttx/lib/lib_internal.h
index c3d9bfd18e..49cba9996f 100644
--- a/nuttx/lib/lib_internal.h
+++ b/nuttx/lib/lib_internal.h
@@ -140,6 +140,7 @@ extern int lib_vsprintf(FAR struct lib_outstream_s *obj,
 /* Defined lib_rawprintf.c */
 
 extern int lib_rawvprintf(const char *src, va_list ap);
+extern int lib_rawvdprintf(int fd, const char *fmt, va_list ap);
 
 /* Defined lib_lowprintf.c */
 
diff --git a/nuttx/lib/stdio/Make.defs b/nuttx/lib/stdio/Make.defs
index f88a5edd9e..a4e9007052 100644
--- a/nuttx/lib/stdio/Make.defs
+++ b/nuttx/lib/stdio/Make.defs
@@ -50,7 +50,7 @@ CSRCS += lib_fopen.c lib_fclose.c lib_fread.c lib_libfread.c lib_fseek.c \
 		   lib_gets.c lib_fwrite.c lib_libfwrite.c lib_fflush.c \
 		   lib_libflushall.c lib_libfflush.c lib_rdflush.c lib_wrflush.c \
 		   lib_fputc.c lib_puts.c lib_fputs.c lib_ungetc.c lib_vprintf.c \
-		   lib_fprintf.c lib_vfprintf.c lib_stdinstream.c lib_stdoutstream.c \
+		   lib_fprintf.c lib_vfprintf.c lib_vdprintf.c lib_stdinstream.c lib_stdoutstream.c \
 		   lib_perror.c
 endif
 endif
diff --git a/nuttx/lib/stdio/lib_rawprintf.c b/nuttx/lib/stdio/lib_rawprintf.c
index 19dfa895e1..1a6eb16b7c 100644
--- a/nuttx/lib/stdio/lib_rawprintf.c
+++ b/nuttx/lib/stdio/lib_rawprintf.c
@@ -149,3 +149,18 @@ int lib_rawprintf(const char *fmt, ...)
 
   return ret;
 }
+
+
+/****************************************************************************
+ * Name: lib_rawvdprintf
+ ****************************************************************************/
+
+int lib_rawvdprintf(int fd, const char *fmt, va_list ap)
+{
+  /* Wrap the stdout in a stream object and let lib_vsprintf
+   * do the work.
+   */
+  struct lib_rawoutstream_s rawoutstream;
+  lib_rawoutstream(&rawoutstream, fd);
+  return lib_vsprintf(&rawoutstream.public, fmt, ap);
+}
diff --git a/nuttx/lib/stdio/lib_vdprintf.c b/nuttx/lib/stdio/lib_vdprintf.c
new file mode 100644
index 0000000000..c2b5761107
--- /dev/null
+++ b/nuttx/lib/stdio/lib_vdprintf.c
@@ -0,0 +1,81 @@
+/****************************************************************************
+ * lib/stdio/lib_vdprintf.c
+ *
+ *   Copyright (C) 2007-2009, 2011 Andrew Tridgell. All rights reserved.
+ *   Author: Andrew Tridgell <andrew@tridgell.net>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdio.h>
+
+#include "lib_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Type Declarations
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int vdprintf(int fd, FAR const char *fmt, va_list ap)
+{
+	return lib_rawvdprintf(fd, fmt, ap);
+}
diff --git a/nuttx/tools/mkdeps.sh b/nuttx/tools/mkdeps.sh
index acb6001509..d8984e5536 100755
--- a/nuttx/tools/mkdeps.sh
+++ b/nuttx/tools/mkdeps.sh
@@ -86,8 +86,12 @@ dodep ()
       fi
     done
     if [ -z "$fullpath" ]; then
-      echo "# ERROR: No readable file for $1 found at any location"
-      show_usage
+	if [ -r $1 ]; then
+	    fullpath=$1
+	else
+	    echo "# ERROR: No readable file for $1 found at any location"
+	    show_usage
+	fi
     fi
   fi