Merge pull request #287 from DrTon/sdlog2

sdlog2 - new APM compatible logger

6 files changed, 1615 insertions, 0 deletions

diff --git a/src/modules/sdlog2/logbuffer.c b/src/modules/sdlog2/logbuffer.c
new file mode 100644
index 000000000..4205bcf20
--- /dev/null
+++ b/src/modules/sdlog2/logbuffer.c
@@ -0,0 +1,133 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 PX4 Development Team. All rights reserved.
+ *   Author: Anton Babushkin <rk3dov@gmail.com>
+ *
+ * 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 PX4 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file logbuffer.c
+ *
+ * Ring FIFO buffer for binary log data.
+ *
+ * @author Anton Babushkin <rk3dov@gmail.com>
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "logbuffer.h"
+
+void logbuffer_init(struct logbuffer_s *lb, int size)
+{
+	lb->size  = size;
+	lb->write_ptr = 0;
+	lb->read_ptr = 0;
+	lb->data = malloc(lb->size);
+}
+
+int logbuffer_count(struct logbuffer_s *lb)
+{
+	int n = lb->write_ptr - lb->read_ptr;
+
+	if (n < 0) {
+		n += lb->size;
+	}
+
+	return n;
+}
+
+int logbuffer_is_empty(struct logbuffer_s *lb)
+{
+	return lb->read_ptr == lb->write_ptr;
+}
+
+bool logbuffer_write(struct logbuffer_s *lb, void *ptr, int size)
+{
+	// bytes available to write
+	int available = lb->read_ptr - lb->write_ptr - 1;
+
+	if (available < 0)
+		available += lb->size;
+
+	if (size > available) {
+		// buffer overflow
+		return false;
+	}
+
+	char *c = (char *) ptr;
+	int n = lb->size - lb->write_ptr;	// bytes to end of the buffer
+
+	if (n < size) {
+		// message goes over end of the buffer
+		memcpy(&(lb->data[lb->write_ptr]), c, n);
+		lb->write_ptr = 0;
+
+	} else {
+		n = 0;
+	}
+
+	// now: n = bytes already written
+	int p = size - n;	// number of bytes to write
+	memcpy(&(lb->data[lb->write_ptr]), &(c[n]), p);
+	lb->write_ptr = (lb->write_ptr + p) % lb->size;
+	return true;
+}
+
+int logbuffer_get_ptr(struct logbuffer_s *lb, void **ptr, bool *is_part)
+{
+	// bytes available to read
+	int available = lb->write_ptr - lb->read_ptr;
+
+	if (available == 0) {
+		return 0;	// buffer is empty
+	}
+
+	int n = 0;
+
+	if (available > 0) {
+		// read pointer is before write pointer, all available bytes can be read
+		n = available;
+		*is_part = false;
+
+	} else {
+		// read pointer is after write pointer, read bytes from read_ptr to end of the buffer
+		n = lb->size - lb->read_ptr;
+		*is_part = true;
+	}
+
+	*ptr = &(lb->data[lb->read_ptr]);
+	return n;
+}
+
+void logbuffer_mark_read(struct logbuffer_s *lb, int n)
+{
+	lb->read_ptr = (lb->read_ptr + n) % lb->size;
+}
diff --git a/src/modules/sdlog2/logbuffer.h b/src/modules/sdlog2/logbuffer.h
new file mode 100644
index 000000000..e9635e5e7
--- /dev/null
+++ b/src/modules/sdlog2/logbuffer.h
@@ -0,0 +1,68 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 PX4 Development Team. All rights reserved.
+ *   Author: Anton Babushkin <rk3dov@gmail.com>
+ *
+ * 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 PX4 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file logbuffer.h
+ *
+ * Ring FIFO buffer for binary log data.
+ *
+ * @author Anton Babushkin <rk3dov@gmail.com>
+ */
+
+#ifndef SDLOG2_RINGBUFFER_H_
+#define SDLOG2_RINGBUFFER_H_
+
+#include <stdbool.h>
+
+struct logbuffer_s {
+	// all pointers are in bytes
+	int write_ptr;
+	int read_ptr;
+	int size;
+	char *data;
+};
+
+void logbuffer_init(struct logbuffer_s *lb, int size);
+
+int logbuffer_count(struct logbuffer_s *lb);
+
+int logbuffer_is_empty(struct logbuffer_s *lb);
+
+bool logbuffer_write(struct logbuffer_s *lb, void *ptr, int size);
+
+int logbuffer_get_ptr(struct logbuffer_s *lb, void **ptr, bool *is_part);
+
+void logbuffer_mark_read(struct logbuffer_s *lb, int n);
+
+#endif
diff --git a/src/modules/sdlog2/module.mk b/src/modules/sdlog2/module.mk
new file mode 100644
index 000000000..f53129688
--- /dev/null
+++ b/src/modules/sdlog2/module.mk
@@ -0,0 +1,43 @@
+############################################################################
+#
+#   Copyright (c) 2013 PX4 Development Team. All rights reserved.
+#
+# 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 PX4 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.
+#
+############################################################################
+
+#
+# sdlog2 Application
+#
+
+MODULE_COMMAND  = sdlog2
+# The main thread only buffers to RAM, needs a high priority
+MODULE_PRIORITY = "SCHED_PRIORITY_MAX-30"
+
+SRCS = sdlog2.c \
+       logbuffer.c
diff --git a/src/modules/sdlog2/sdlog2.c b/src/modules/sdlog2/sdlog2.c
new file mode 100644
index 000000000..b5821098f
--- /dev/null
+++ b/src/modules/sdlog2/sdlog2.c
@@ -0,0 +1,1121 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2012, 2013 PX4 Development Team. All rights reserved.
+ *   Author: Lorenz Meier <lm@inf.ethz.ch>
+ *           Anton Babushkin <rk3dov@gmail.com>
+ *
+ * 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 PX4 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file sdlog2.c
+ *
+ * Simple SD logger for flight data. Buffers new sensor values and
+ * does the heavy SD I/O in a low-priority worker thread.
+ *
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ * @author Anton Babushkin <rk3dov@gmail.com>
+ */
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/prctl.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <poll.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <systemlib/err.h>
+#include <unistd.h>
+#include <drivers/drv_hrt.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/sensor_combined.h>
+#include <uORB/topics/vehicle_attitude.h>
+#include <uORB/topics/vehicle_attitude_setpoint.h>
+#include <uORB/topics/actuator_outputs.h>
+#include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/actuator_controls_effective.h>
+#include <uORB/topics/vehicle_command.h>
+#include <uORB/topics/vehicle_local_position.h>
+#include <uORB/topics/vehicle_local_position_setpoint.h>
+#include <uORB/topics/vehicle_global_position.h>
+#include <uORB/topics/vehicle_gps_position.h>
+#include <uORB/topics/vehicle_vicon_position.h>
+#include <uORB/topics/optical_flow.h>
+#include <uORB/topics/battery_status.h>
+#include <uORB/topics/differential_pressure.h>
+#include <uORB/topics/airspeed.h>
+
+#include <systemlib/systemlib.h>
+
+#include <mavlink/mavlink_log.h>
+
+#include "logbuffer.h"
+#include "sdlog2_format.h"
+#include "sdlog2_messages.h"
+
+#define LOGBUFFER_WRITE_AND_COUNT(_msg) if (logbuffer_write(&lb, &log_msg, LOG_PACKET_SIZE(_msg))) { \
+		log_msgs_written++; \
+	} else { \
+		log_msgs_skipped++; \
+		/*printf("skip\n");*/ \
+	}
+
+#define LOG_ORB_SUBSCRIBE(_var, _topic) subs.##_var##_sub = orb_subscribe(ORB_ID(##_topic##)); \
+		fds[fdsc_count].fd = subs.##_var##_sub; \
+		fds[fdsc_count].events = POLLIN; \
+		fdsc_count++;
+
+
+//#define SDLOG2_DEBUG
+
+static bool thread_should_exit = false;		/**< Deamon exit flag */
+static bool thread_running = false;			/**< Deamon status flag */
+static int deamon_task;						/**< Handle of deamon task / thread */
+static bool logwriter_should_exit = false;	/**< Logwriter thread exit flag */
+static const int MAX_NO_LOGFOLDER = 999;	/**< Maximum number of log folders */
+static const int MAX_NO_LOGFILE = 999;		/**< Maximum number of log files */
+static const int LOG_BUFFER_SIZE = 8192;
+static const int MAX_WRITE_CHUNK = 512;
+static const int MIN_BYTES_TO_WRITE = 512;
+
+static const char *mountpoint = "/fs/microsd";
+int log_file = -1;
+int mavlink_fd = -1;
+struct logbuffer_s lb;
+
+/* mutex / condition to synchronize threads */
+pthread_mutex_t logbuffer_mutex;
+pthread_cond_t logbuffer_cond;
+
+char folder_path[64];
+
+/* statistics counters */
+unsigned long log_bytes_written = 0;
+uint64_t start_time = 0;
+unsigned long log_msgs_written = 0;
+unsigned long log_msgs_skipped = 0;
+
+/* current state of logging */
+bool logging_enabled = false;
+/* enable logging on start (-e option) */
+bool log_on_start = false;
+/* enable logging when armed (-a option) */
+bool log_when_armed = false;
+/* delay = 1 / rate (rate defined by -r option) */
+useconds_t sleep_delay = 0;
+
+/* helper flag to track system state changes */
+bool flag_system_armed = false;
+
+pthread_t logwriter_pthread = 0;
+
+/**
+ * Log buffer writing thread. Open and close file here.
+ */
+static void *logwriter_thread(void *arg);
+
+/**
+ * SD log management function.
+ */
+__EXPORT int sdlog2_main(int argc, char *argv[]);
+
+/**
+ * Mainloop of sd log deamon.
+ */
+int sdlog2_thread_main(int argc, char *argv[]);
+
+/**
+ * Print the correct usage.
+ */
+static void sdlog2_usage(const char *reason);
+
+/**
+ * Print the current status.
+ */
+static void sdlog2_status(void);
+
+/**
+ * Start logging: create new file and start log writer thread.
+ */
+void sdlog2_start_log();
+
+/**
+ * Stop logging: stop log writer thread and close log file.
+ */
+void sdlog2_stop_log();
+
+/**
+ * Write a header to log file: list of message formats.
+ */
+void write_formats(int fd);
+
+
+static bool file_exist(const char *filename);
+
+static int file_copy(const char *file_old, const char *file_new);
+
+static void handle_command(struct vehicle_command_s *cmd);
+
+static void handle_status(struct vehicle_status_s *cmd);
+
+/**
+ * Create folder for current logging session. Store folder name in 'log_folder'.
+ */
+static int create_logfolder();
+
+/**
+ * Select first free log file name and open it.
+ */
+static int open_logfile();
+
+static void
+sdlog2_usage(const char *reason)
+{
+	if (reason)
+		fprintf(stderr, "%s\n", reason);
+
+	errx(1, "usage: sdlog2 {start|stop|status} [-r <log rate>] -e -a\n"
+	     "\t-r\tLog rate in Hz, 0 means unlimited rate\n"
+	     "\t-e\tEnable logging by default (if not, can be started by command)\n"
+	     "\t-a\tLog only when armed (can be still overriden by command)\n");
+}
+
+/**
+ * The logger deamon app only briefly exists to start
+ * the background job. The stack size assigned in the
+ * Makefile does only apply to this management task.
+ *
+ * The actual stack size should be set in the call
+ * to task_spawn().
+ */
+int sdlog2_main(int argc, char *argv[])
+{
+	if (argc < 2)
+		sdlog2_usage("missing command");
+
+	if (!strcmp(argv[1], "start")) {
+
+		if (thread_running) {
+			printf("sdlog2 already running\n");
+			/* this is not an error */
+			exit(0);
+		}
+
+		thread_should_exit = false;
+		deamon_task = task_spawn("sdlog2",
+					 SCHED_DEFAULT,
+					 SCHED_PRIORITY_DEFAULT - 30,
+					 2048,
+					 sdlog2_thread_main,
+					 (const char **)argv);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+		if (!thread_running) {
+			printf("\tsdlog2 is not started\n");
+		}
+
+		thread_should_exit = true;
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			sdlog2_status();
+
+		} else {
+			printf("\tsdlog2 not started\n");
+		}
+
+		exit(0);
+	}
+
+	sdlog2_usage("unrecognized command");
+	exit(1);
+}
+
+int create_logfolder()
+{
+	/* make folder on sdcard */
+	uint16_t folder_number = 1; // start with folder sess001
+	int mkdir_ret;
+
+	/* look for the next folder that does not exist */
+	while (folder_number <= MAX_NO_LOGFOLDER) {
+		/* set up folder path: e.g. /fs/microsd/sess001 */
+		sprintf(folder_path, "%s/sess%03u", mountpoint, folder_number);
+		mkdir_ret = mkdir(folder_path, S_IRWXU | S_IRWXG | S_IRWXO);
+		/* the result is -1 if the folder exists */
+
+		if (mkdir_ret == 0) {
+			/* folder does not exist, success */
+
+			/* copy parser script file */
+			// TODO
+			/*
+			char mfile_out[100];
+			sprintf(mfile_out, "%s/session%04u/run_to_plot_data.m", mountpoint, foldernumber);
+			int ret = file_copy(mfile_in, mfile_out);
+
+			if (!ret) {
+				warnx("copied m file to %s", mfile_out);
+
+			} else {
+				warnx("failed copying m file from %s to\n %s", mfile_in, mfile_out);
+			}
+			*/
+
+			break;
+
+		} else if (mkdir_ret == -1) {
+			/* folder exists already */
+			folder_number++;
+			continue;
+
+		} else {
+			warn("failed creating new folder");
+			return -1;
+		}
+	}
+
+	if (folder_number >= MAX_NO_LOGFOLDER) {
+		/* we should not end up here, either we have more than MAX_NO_LOGFOLDER on the SD card, or another problem */
+		warnx("all %d possible folders exist already.", MAX_NO_LOGFOLDER);
+		return -1;
+	}
+
+	return 0;
+}
+
+int open_logfile()
+{
+	/* make folder on sdcard */
+	uint16_t file_number = 1; // start with file log001
+
+	/* string to hold the path to the log */
+	char path_buf[64] = "";
+
+	int fd = 0;
+
+	/* look for the next file that does not exist */
+	while (file_number <= MAX_NO_LOGFILE) {
+		/* set up file path: e.g. /fs/microsd/sess001/log001.bin */
+		sprintf(path_buf, "%s/log%03u.bin", folder_path, file_number);
+
+		if (file_exist(path_buf)) {
+			file_number++;
+			continue;
+		}
+
+		fd = open(path_buf, O_CREAT | O_WRONLY | O_DSYNC);
+
+		if (fd == 0) {
+			errx(1, "opening %s failed.", path_buf);
+		}
+
+		warnx("logging to: %s", path_buf);
+		mavlink_log_info(mavlink_fd, "[sdlog2] log: %s", path_buf);
+
+		return fd;
+	}
+
+	if (file_number > MAX_NO_LOGFILE) {
+		/* we should not end up here, either we have more than MAX_NO_LOGFILE on the SD card, or another problem */
+		warn("all %d possible files exist already", MAX_NO_LOGFILE);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void *logwriter_thread(void *arg)
+{
+	/* set name */
+	prctl(PR_SET_NAME, "sdlog2_writer", 0);
+
+	struct logbuffer_s *logbuf = (struct logbuffer_s *)arg;
+
+	int log_file = open_logfile();
+
+	/* write log messages formats */
+	write_formats(log_file);
+
+	int poll_count = 0;
+
+	void *read_ptr;
+	int n = 0;
+	bool should_wait = false;
+	bool is_part = false;
+
+	while (!thread_should_exit && !logwriter_should_exit) {
+
+		/* make sure threads are synchronized */
+		pthread_mutex_lock(&logbuffer_mutex);
+
+		/* update read pointer if needed */
+		if (n > 0) {
+			logbuffer_mark_read(&lb, n);
+		}
+
+		/* only wait if no data is available to process */
+		if (should_wait) {
+			/* blocking wait for new data at this line */
+			pthread_cond_wait(&logbuffer_cond, &logbuffer_mutex);
+		}
+
+		/* only get pointer to thread-safe data, do heavy I/O a few lines down */
+		int available = logbuffer_get_ptr(logbuf, &read_ptr, &is_part);
+
+		/* continue */
+		pthread_mutex_unlock(&logbuffer_mutex);
+
+		if (available > 0) {
+			/* do heavy IO here */
+			if (available > MAX_WRITE_CHUNK) {
+				n = MAX_WRITE_CHUNK;
+
+			} else {
+				n = available;
+			}
+
+			n = write(log_file, read_ptr, n);
+
+			should_wait = (n == available) && !is_part;
+#ifdef SDLOG2_DEBUG
+			printf("%i wrote: %i of %i, is_part=%i, should_wait=%i", poll_count, n, available, (int)is_part, (int)should_wait);
+#endif
+
+			if (n < 0) {
+				thread_should_exit = true;
+				err(1, "error writing log file");
+			}
+
+			if (n > 0) {
+				log_bytes_written += n;
+			}
+
+		} else {
+			should_wait = true;
+		}
+
+		if (poll_count % 10 == 0) {
+			fsync(log_file);
+		}
+
+		poll_count++;
+	}
+
+	fsync(log_file);
+	close(log_file);
+
+	return OK;
+}
+
+void sdlog2_start_log()
+{
+	warnx("start logging.");
+	mavlink_log_info(mavlink_fd, "[sdlog2] start logging");
+
+	/* initialize statistics counter */
+	log_bytes_written = 0;
+	start_time = hrt_absolute_time();
+	log_msgs_written = 0;
+	log_msgs_skipped = 0;
+
+	/* initialize log buffer emptying thread */
+	pthread_attr_t receiveloop_attr;
+	pthread_attr_init(&receiveloop_attr);
+
+	struct sched_param param;
+	/* low priority, as this is expensive disk I/O */
+	param.sched_priority = SCHED_PRIORITY_DEFAULT - 40;
+	(void)pthread_attr_setschedparam(&receiveloop_attr, &param);
+
+	pthread_attr_setstacksize(&receiveloop_attr, 2048);
+
+	logwriter_should_exit = false;
+	pthread_t thread;
+
+	/* start log buffer emptying thread */
+	if (0 != pthread_create(&thread, &receiveloop_attr, logwriter_thread, &lb)) {
+		errx(1, "error creating logwriter thread");
+	}
+
+	logging_enabled = true;
+	// XXX we have to destroy the attr at some point
+}
+
+void sdlog2_stop_log()
+{
+	warnx("stop logging.");
+	mavlink_log_info(mavlink_fd, "[sdlog2] stop logging");
+
+	logging_enabled = true;
+	logwriter_should_exit = true;
+
+	/* wake up write thread one last time */
+	pthread_mutex_lock(&logbuffer_mutex);
+	pthread_cond_signal(&logbuffer_cond);
+	/* unlock, now the writer thread may return */
+	pthread_mutex_unlock(&logbuffer_mutex);
+
+	/* wait for write thread to return */
+	(void)pthread_join(logwriter_pthread, NULL);
+
+	sdlog2_status();
+}
+
+
+void write_formats(int fd)
+{
+	/* construct message format packet */
+	struct {
+		LOG_PACKET_HEADER;
+		struct log_format_s body;
+	} log_format_packet = {
+		LOG_PACKET_HEADER_INIT(LOG_FORMAT_MSG),
+	};
+
+	/* fill message format packet for each format and write to log */
+	int i;
+
+	for (i = 0; i < log_formats_num; i++) {
+		log_format_packet.body = log_formats[i];
+		write(fd, &log_format_packet, sizeof(log_format_packet));
+	}
+
+	fsync(fd);
+}
+
+int sdlog2_thread_main(int argc, char *argv[])
+{
+	mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
+
+	if (mavlink_fd < 0) {
+		warnx("failed to open MAVLink log stream, start mavlink app first.");
+	}
+
+	/* log every n'th value (skip three per default) */
+	int skip_value = 3;
+
+	/* work around some stupidity in task_create's argv handling */
+	argc -= 2;
+	argv += 2;
+	int ch;
+
+	while ((ch = getopt(argc, argv, "r:ea")) != EOF) {
+		switch (ch) {
+		case 'r': {
+				unsigned r = strtoul(optarg, NULL, 10);
+
+				if (r == 0) {
+					sleep_delay = 0;
+
+				} else {
+					sleep_delay = 1000000 / r;
+				}
+			}
+			break;
+
+		case 'e':
+			log_on_start = true;
+			break;
+
+		case 'a':
+			log_when_armed = true;
+			break;
+
+		case '?':
+			if (optopt == 'c') {
+				warnx("Option -%c requires an argument.", optopt);
+
+			} else if (isprint(optopt)) {
+				warnx("Unknown option `-%c'.", optopt);
+
+			} else {
+				warnx("Unknown option character `\\x%x'.", optopt);
+			}
+
+		default:
+			sdlog2_usage("unrecognized flag");
+			errx(1, "exiting");
+		}
+	}
+
+	if (!file_exist(mountpoint)) {
+		errx(1, "logging mount point %s not present, exiting.", mountpoint);
+	}
+
+	if (create_logfolder())
+		errx(1, "unable to create logging folder, exiting.");
+
+	/* only print logging path, important to find log file later */
+	warnx("logging to directory: %s", folder_path);
+
+	/* file descriptors to wait for */
+	struct pollfd fds_control[2];
+
+	/* --- IMPORTANT: DEFINE NUMBER OF ORB STRUCTS TO WAIT FOR HERE --- */
+	/* number of messages */
+	const ssize_t fdsc = 15;
+	/* Sanity check variable and index */
+	ssize_t fdsc_count = 0;
+	/* file descriptors to wait for */
+	struct pollfd fds[fdsc];
+
+	/* warning! using union here to save memory, elements should be used separately! */
+	union {
+		struct vehicle_command_s cmd;
+		struct vehicle_status_s status;
+		struct sensor_combined_s sensor;
+		struct vehicle_attitude_s att;
+		struct vehicle_attitude_setpoint_s att_sp;
+		struct actuator_outputs_s act_outputs;
+		struct actuator_controls_s act_controls;
+		struct actuator_controls_effective_s act_controls_effective;
+		struct vehicle_local_position_s local_pos;
+		struct vehicle_local_position_setpoint_s local_pos_sp;
+		struct vehicle_global_position_s global_pos;
+		struct vehicle_gps_position_s gps_pos;
+		struct vehicle_vicon_position_s vicon_pos;
+		struct optical_flow_s flow;
+		struct battery_status_s batt;
+		struct differential_pressure_s diff_pres;
+		struct airspeed_s airspeed;
+	} buf;
+	memset(&buf, 0, sizeof(buf));
+
+	struct {
+		int cmd_sub;
+		int status_sub;
+		int sensor_sub;
+		int att_sub;
+		int att_sp_sub;
+		int act_outputs_sub;
+		int act_controls_sub;
+		int act_controls_effective_sub;
+		int local_pos_sub;
+		int local_pos_sp_sub;
+		int global_pos_sub;
+		int gps_pos_sub;
+		int vicon_pos_sub;
+		int flow_sub;
+		int batt_sub;
+		int diff_pres_sub;
+		int airspeed_sub;
+	} subs;
+
+	/* log message buffer: header + body */
+#pragma pack(push, 1)
+	struct {
+		LOG_PACKET_HEADER;
+		union {
+			struct log_TIME_s log_TIME;
+			struct log_ATT_s log_ATT;
+			struct log_ATSP_s log_ATSP;
+			struct log_IMU_s log_IMU;
+			struct log_SENS_s log_SENS;
+			struct log_LPOS_s log_LPOS;
+			struct log_LPSP_s log_LPSP;
+			struct log_GPS_s log_GPS;
+		} body;
+	} log_msg = {
+		LOG_PACKET_HEADER_INIT(0)
+	};
+#pragma pack(pop)
+	memset(&log_msg.body, 0, sizeof(log_msg.body));
+
+	/* --- VEHICLE COMMAND --- */
+	subs.cmd_sub = orb_subscribe(ORB_ID(vehicle_command));
+	fds[fdsc_count].fd = subs.cmd_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- VEHICLE STATUS --- */
+	subs.status_sub = orb_subscribe(ORB_ID(vehicle_status));
+	fds[fdsc_count].fd = subs.status_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- GPS POSITION --- */
+	subs.gps_pos_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
+	fds[fdsc_count].fd = subs.gps_pos_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- SENSORS COMBINED --- */
+	subs.sensor_sub = orb_subscribe(ORB_ID(sensor_combined));
+	fds[fdsc_count].fd = subs.sensor_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- ATTITUDE --- */
+	subs.att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
+	fds[fdsc_count].fd = subs.att_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- ATTITUDE SETPOINT --- */
+	subs.att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
+	fds[fdsc_count].fd = subs.att_sp_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- ACTUATOR OUTPUTS --- */
+	subs.act_outputs_sub = orb_subscribe(ORB_ID(actuator_outputs_0));
+	fds[fdsc_count].fd = subs.act_outputs_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- ACTUATOR CONTROL --- */
+	subs.act_controls_sub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS);
+	fds[fdsc_count].fd = subs.act_controls_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- ACTUATOR CONTROL EFFECTIVE --- */
+	subs.act_controls_effective_sub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS_EFFECTIVE);
+	fds[fdsc_count].fd = subs.act_controls_effective_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- LOCAL POSITION --- */
+	subs.local_pos_sub = orb_subscribe(ORB_ID(vehicle_local_position));
+	fds[fdsc_count].fd = subs.local_pos_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- LOCAL POSITION SETPOINT --- */
+	subs.local_pos_sp_sub = orb_subscribe(ORB_ID(vehicle_local_position_setpoint));
+	fds[fdsc_count].fd = subs.local_pos_sp_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- GLOBAL POSITION --- */
+	subs.global_pos_sub = orb_subscribe(ORB_ID(vehicle_global_position));
+	fds[fdsc_count].fd = subs.global_pos_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- VICON POSITION --- */
+	subs.vicon_pos_sub = orb_subscribe(ORB_ID(vehicle_vicon_position));
+	fds[fdsc_count].fd = subs.vicon_pos_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- OPTICAL FLOW --- */
+	subs.flow_sub = orb_subscribe(ORB_ID(optical_flow));
+	fds[fdsc_count].fd = subs.flow_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* --- BATTERY STATUS --- */
+	subs.batt_sub = orb_subscribe(ORB_ID(battery_status));
+	fds[fdsc_count].fd = subs.batt_sub;
+	fds[fdsc_count].events = POLLIN;
+	fdsc_count++;
+
+	/* WARNING: If you get the error message below,
+	 * then the number of registered messages (fdsc)
+	 * differs from the number of messages in the above list.
+	 */
+	if (fdsc_count > fdsc) {
+		warn("WARNING: Not enough space for poll fds allocated. Check %s:%d.", __FILE__, __LINE__);
+		fdsc_count = fdsc;
+	}
+
+	/*
+	 * set up poll to block for new data,
+	 * wait for a maximum of 1000 ms
+	 */
+	const int poll_timeout = 1000;
+
+	thread_running = true;
+
+	/* initialize log buffer with specified size */
+	logbuffer_init(&lb, LOG_BUFFER_SIZE);
+
+	/* initialize thread synchronization */
+	pthread_mutex_init(&logbuffer_mutex, NULL);
+	pthread_cond_init(&logbuffer_cond, NULL);
+
+	/* track changes in sensor_combined topic */
+	uint16_t gyro_counter = 0;
+	uint16_t accelerometer_counter = 0;
+	uint16_t magnetometer_counter = 0;
+	uint16_t baro_counter = 0;
+	uint16_t differential_pressure_counter = 0;
+
+	/* enable logging on start if needed */
+	if (log_on_start)
+		sdlog2_start_log();
+
+	while (!thread_should_exit) {
+		/* decide use usleep() or blocking poll() */
+		bool use_sleep = sleep_delay > 0 && logging_enabled;
+
+		/* poll all topics if logging enabled or only management (first 2) if not */
+		int poll_ret = poll(fds, logging_enabled ? fdsc_count : 2, use_sleep ? 0 : poll_timeout);
+
+		/* handle the poll result */
+		if (poll_ret < 0) {
+			warnx("ERROR: poll error, stop logging.");
+			thread_should_exit = true;
+
+		} else if (poll_ret > 0) {
+
+			/* check all data subscriptions only if logging enabled,
+			 * logging_enabled can be changed while checking vehicle_command and vehicle_status */
+			bool check_data = logging_enabled;
+			int ifds = 0;
+
+			/* --- VEHICLE COMMAND --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_command), subs.cmd_sub, &buf.cmd);
+				handle_command(&buf.cmd);
+			}
+
+			/* --- VEHICLE STATUS --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_status), subs.status_sub, &buf.status);
+				if (log_when_armed) {
+					handle_status(&buf.status);
+				}
+			}
+
+			if (!logging_enabled || !check_data) {
+				continue;
+			}
+
+			pthread_mutex_lock(&logbuffer_mutex);
+
+			/* write time stamp message */
+			log_msg.msg_type = LOG_TIME_MSG;
+			log_msg.body.log_TIME.t = hrt_absolute_time();
+			LOGBUFFER_WRITE_AND_COUNT(TIME);
+
+			/* --- GPS POSITION --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_gps_position), subs.gps_pos_sub, &buf.gps_pos);
+				log_msg.msg_type = LOG_GPS_MSG;
+				log_msg.body.log_GPS.gps_time = buf.gps_pos.time_gps_usec;
+				log_msg.body.log_GPS.fix_type = buf.gps_pos.fix_type;
+				log_msg.body.log_GPS.eph = buf.gps_pos.eph_m;
+				log_msg.body.log_GPS.epv = buf.gps_pos.epv_m;
+				log_msg.body.log_GPS.lat = buf.gps_pos.lat;
+				log_msg.body.log_GPS.lon = buf.gps_pos.lon;
+				log_msg.body.log_GPS.alt = buf.gps_pos.alt * 0.001;
+				log_msg.body.log_GPS.vel_n = buf.gps_pos.vel_n_m_s;
+				log_msg.body.log_GPS.vel_e = buf.gps_pos.vel_e_m_s;
+				log_msg.body.log_GPS.vel_d = buf.gps_pos.vel_d_m_s;
+				log_msg.body.log_GPS.cog = buf.gps_pos.cog_rad;
+				LOGBUFFER_WRITE_AND_COUNT(GPS);
+			}
+
+			/* --- SENSOR COMBINED --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(sensor_combined), subs.sensor_sub, &buf.sensor);
+				bool write_IMU = false;
+				bool write_SENS = false;
+
+				if (buf.sensor.gyro_counter != gyro_counter) {
+					gyro_counter = buf.sensor.gyro_counter;
+					write_IMU = true;
+				}
+
+				if (buf.sensor.accelerometer_counter != accelerometer_counter) {
+					accelerometer_counter = buf.sensor.accelerometer_counter;
+					write_IMU = true;
+				}
+
+				if (buf.sensor.magnetometer_counter != magnetometer_counter) {
+					magnetometer_counter = buf.sensor.magnetometer_counter;
+					write_IMU = true;
+				}
+
+				if (buf.sensor.baro_counter != baro_counter) {
+					baro_counter = buf.sensor.baro_counter;
+					write_SENS = true;
+				}
+
+				if (buf.sensor.differential_pressure_counter != differential_pressure_counter) {
+					differential_pressure_counter = buf.sensor.differential_pressure_counter;
+					write_SENS = true;
+				}
+
+				if (write_IMU) {
+					log_msg.msg_type = LOG_IMU_MSG;
+					log_msg.body.log_IMU.gyro_x = buf.sensor.gyro_rad_s[0];
+					log_msg.body.log_IMU.gyro_y = buf.sensor.gyro_rad_s[1];
+					log_msg.body.log_IMU.gyro_z = buf.sensor.gyro_rad_s[2];
+					log_msg.body.log_IMU.acc_x = buf.sensor.accelerometer_m_s2[0];
+					log_msg.body.log_IMU.acc_y = buf.sensor.accelerometer_m_s2[1];
+					log_msg.body.log_IMU.acc_z = buf.sensor.accelerometer_m_s2[2];
+					log_msg.body.log_IMU.mag_x = buf.sensor.magnetometer_ga[0];
+					log_msg.body.log_IMU.mag_y = buf.sensor.magnetometer_ga[1];
+					log_msg.body.log_IMU.mag_z = buf.sensor.magnetometer_ga[2];
+					LOGBUFFER_WRITE_AND_COUNT(IMU);
+				}
+
+				if (write_SENS) {
+					log_msg.msg_type = LOG_SENS_MSG;
+					log_msg.body.log_SENS.baro_pres = buf.sensor.baro_pres_mbar;
+					log_msg.body.log_SENS.baro_alt = buf.sensor.baro_alt_meter;
+					log_msg.body.log_SENS.baro_temp = buf.sensor.baro_temp_celcius;
+					log_msg.body.log_SENS.diff_pres = buf.sensor.differential_pressure_pa;
+					LOGBUFFER_WRITE_AND_COUNT(SENS);
+				}
+			}
+
+			/* --- ATTITUDE --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_attitude), subs.att_sub, &buf.att);
+				log_msg.msg_type = LOG_ATT_MSG;
+				log_msg.body.log_ATT.roll = buf.att.roll;
+				log_msg.body.log_ATT.pitch = buf.att.pitch;
+				log_msg.body.log_ATT.yaw = buf.att.yaw;
+				LOGBUFFER_WRITE_AND_COUNT(ATT);
+			}
+
+			/* --- ATTITUDE SETPOINT --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_attitude_setpoint), subs.att_sp_sub, &buf.att_sp);
+				log_msg.msg_type = LOG_ATSP_MSG;
+				log_msg.body.log_ATSP.roll_sp = buf.att_sp.roll_body;
+				log_msg.body.log_ATSP.pitch_sp = buf.att_sp.pitch_body;
+				log_msg.body.log_ATSP.yaw_sp = buf.att_sp.yaw_body;
+				LOGBUFFER_WRITE_AND_COUNT(ATSP);
+			}
+
+			/* --- ACTUATOR OUTPUTS --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(actuator_outputs_0), subs.act_outputs_sub, &buf.act_outputs);
+				// TODO not implemented yet
+			}
+
+			/* --- ACTUATOR CONTROL --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, subs.act_controls_sub, &buf.act_controls);
+				// TODO not implemented yet
+			}
+
+			/* --- ACTUATOR CONTROL EFFECTIVE --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS_EFFECTIVE, subs.act_controls_effective_sub, &buf.act_controls_effective);
+				// TODO not implemented yet
+			}
+
+			/* --- LOCAL POSITION --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_local_position), subs.local_pos_sub, &buf.local_pos);
+				log_msg.msg_type = LOG_LPOS_MSG;
+				log_msg.body.log_LPOS.x = buf.local_pos.x;
+				log_msg.body.log_LPOS.y = buf.local_pos.y;
+				log_msg.body.log_LPOS.z = buf.local_pos.z;
+				log_msg.body.log_LPOS.vx = buf.local_pos.vx;
+				log_msg.body.log_LPOS.vy = buf.local_pos.vy;
+				log_msg.body.log_LPOS.vz = buf.local_pos.vz;
+				log_msg.body.log_LPOS.hdg = buf.local_pos.hdg;
+				log_msg.body.log_LPOS.home_lat = buf.local_pos.home_lat;
+				log_msg.body.log_LPOS.home_lon = buf.local_pos.home_lon;
+				log_msg.body.log_LPOS.home_alt = buf.local_pos.home_alt;
+				LOGBUFFER_WRITE_AND_COUNT(LPOS);
+			}
+
+			/* --- LOCAL POSITION SETPOINT --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_local_position_setpoint), subs.local_pos_sp_sub, &buf.local_pos_sp);
+				log_msg.msg_type = LOG_LPSP_MSG;
+				log_msg.body.log_LPSP.x = buf.local_pos_sp.x;
+				log_msg.body.log_LPSP.y = buf.local_pos_sp.y;
+				log_msg.body.log_LPSP.z = buf.local_pos_sp.z;
+				log_msg.body.log_LPSP.yaw = buf.local_pos_sp.yaw;
+				LOGBUFFER_WRITE_AND_COUNT(LPSP);
+			}
+
+			/* --- GLOBAL POSITION --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_global_position), subs.global_pos_sub, &buf.global_pos);
+				// TODO not implemented yet
+			}
+
+			/* --- VICON POSITION --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(vehicle_vicon_position), subs.vicon_pos_sub, &buf.vicon_pos);
+				// TODO not implemented yet
+			}
+
+			/* --- FLOW --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(optical_flow), subs.flow_sub, &buf.flow);
+				// TODO not implemented yet
+			}
+
+			/* --- BATTERY STATUS --- */
+			if (fds[ifds++].revents & POLLIN) {
+				orb_copy(ORB_ID(battery_status), subs.batt_sub, &buf.batt);
+				// TODO not implemented yet
+			}
+
+			/* signal the other thread new data, but not yet unlock */
+			if (logbuffer_count(&lb) > MIN_BYTES_TO_WRITE) {
+#ifdef SDLOG2_DEBUG
+				printf("signal %i", logbuffer_count(&lb));
+#endif
+				/* only request write if several packets can be written at once */
+				pthread_cond_signal(&logbuffer_cond);
+			}
+
+			/* unlock, now the writer thread may run */
+			pthread_mutex_unlock(&logbuffer_mutex);
+		}
+
+		if (use_sleep) {
+			usleep(sleep_delay);
+		}
+	}
+
+	if (logging_enabled)
+		sdlog2_stop_log();
+
+	pthread_mutex_destroy(&logbuffer_mutex);
+	pthread_cond_destroy(&logbuffer_cond);
+
+	warnx("exiting.");
+
+	thread_running = false;
+
+	return 0;
+}
+
+void sdlog2_status()
+{
+	float mebibytes = log_bytes_written / 1024.0f / 1024.0f;
+	float seconds = ((float)(hrt_absolute_time() - start_time)) / 1000000.0f;
+
+	warnx("wrote %lu msgs, %4.2f MiB (average %5.3f MiB/s), skipped %lu msgs.", log_msgs_written, (double)mebibytes, (double)(mebibytes / seconds), log_msgs_skipped);
+}
+
+/**
+ * @return 0 if file exists
+ */
+bool file_exist(const char *filename)
+{
+	struct stat buffer;
+	return stat(filename, &buffer) == 0;
+}
+
+int file_copy(const char *file_old, const char *file_new)
+{
+	FILE *source, *target;
+	source = fopen(file_old, "r");
+	int ret = 0;
+
+	if (source == NULL) {
+		warnx("failed opening input file to copy.");
+		return 1;
+	}
+
+	target = fopen(file_new, "w");
+
+	if (target == NULL) {
+		fclose(source);
+		warnx("failed to open output file to copy.");
+		return 1;
+	}
+
+	char buf[128];
+	int nread;
+
+	while ((nread = fread(buf, 1, sizeof(buf), source)) > 0) {
+		ret = fwrite(buf, 1, nread, target);
+
+		if (ret <= 0) {
+			warnx("error writing file.");
+			ret = 1;
+			break;
+		}
+	}
+
+	fsync(fileno(target));
+
+	fclose(source);
+	fclose(target);
+
+	return ret;
+}
+
+void handle_command(struct vehicle_command_s *cmd)
+{
+	/* result of the command */
+	uint8_t result = VEHICLE_CMD_RESULT_UNSUPPORTED;
+	int param;
+
+	/* request to set different system mode */
+	switch (cmd->command) {
+
+	case VEHICLE_CMD_PREFLIGHT_STORAGE:
+		param = (int)(cmd->param3);
+
+		if (param == 1)	{
+			sdlog2_start_log();
+
+		} else if (param == 0)	{
+			sdlog2_stop_log();
+		}
+
+		break;
+
+	default:
+		/* silently ignore */
+		break;
+	}
+}
+
+void handle_status(struct vehicle_status_s *status)
+{
+	if (status->flag_system_armed != flag_system_armed) {
+		flag_system_armed = status->flag_system_armed;
+
+		if (flag_system_armed) {
+			sdlog2_start_log();
+
+		} else {
+			sdlog2_stop_log();
+		}
+	}
+}
diff --git a/src/modules/sdlog2/sdlog2_format.h b/src/modules/sdlog2/sdlog2_format.h
new file mode 100644
index 000000000..59b91d90d
--- /dev/null
+++ b/src/modules/sdlog2/sdlog2_format.h
@@ -0,0 +1,98 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 PX4 Development Team. All rights reserved.
+ *   Author: Anton Babushkin <rk3dov@gmail.com>
+ *
+ * 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 PX4 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file sdlog2_format.h
+ *
+ * General log format structures and macro.
+ *
+ * @author Anton Babushkin <rk3dov@gmail.com>
+ */
+
+/*
+Format characters in the format string for binary log messages
+  b   : int8_t
+  B   : uint8_t
+  h   : int16_t
+  H   : uint16_t
+  i   : int32_t
+  I   : uint32_t
+  f   : float
+  n   : char[4]
+  N   : char[16]
+  Z   : char[64]
+  c   : int16_t * 100
+  C   : uint16_t * 100
+  e   : int32_t * 100
+  E   : uint32_t * 100
+  L   : int32_t latitude/longitude
+  M   : uint8_t flight mode
+
+  q   : int64_t
+  Q   : uint64_t
+ */
+
+#ifndef SDLOG2_FORMAT_H_
+#define SDLOG2_FORMAT_H_
+
+#define LOG_PACKET_HEADER_LEN	   3
+#define LOG_PACKET_HEADER	       uint8_t head1, head2, msg_type;
+#define LOG_PACKET_HEADER_INIT(id) .head1 = HEAD_BYTE1, .head2 = HEAD_BYTE2, .msg_type = id
+
+// once the logging code is all converted we will remove these from
+// this header
+#define HEAD_BYTE1  0xA3    // Decimal 163
+#define HEAD_BYTE2  0x95    // Decimal 149
+
+struct log_format_s {
+	uint8_t type;
+	uint8_t length;		// full packet length including header
+	char name[4];
+	char format[16];
+	char labels[64];
+};
+
+#define LOG_FORMAT(_name, _format, _labels) { \
+		.type = LOG_##_name##_MSG, \
+		.length = sizeof(struct log_##_name##_s) + LOG_PACKET_HEADER_LEN, \
+		.name = #_name, \
+		.format = _format, \
+		.labels = _labels \
+	}
+
+#define LOG_FORMAT_MSG	  0x80
+
+#define LOG_PACKET_SIZE(_name)	LOG_PACKET_HEADER_LEN + sizeof(struct log_##_name##_s)
+
+#endif /* SDLOG2_FORMAT_H_ */
diff --git a/src/modules/sdlog2/sdlog2_messages.h b/src/modules/sdlog2/sdlog2_messages.h
new file mode 100644
index 000000000..316459b1e
--- /dev/null
+++ b/src/modules/sdlog2/sdlog2_messages.h
@@ -0,0 +1,152 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 PX4 Development Team. All rights reserved.
+ *   Author: Anton Babushkin <rk3dov@gmail.com>
+ *
+ * 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 PX4 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file sdlog2_messages.h
+ *
+ * Log messages and structures definition.
+ *
+ * @author Anton Babushkin <rk3dov@gmail.com>
+ */
+
+#ifndef SDLOG2_MESSAGES_H_
+#define SDLOG2_MESSAGES_H_
+
+#include "sdlog2_format.h"
+
+/* define message formats */
+
+#pragma pack(push, 1)
+/* --- TIME - TIME STAMP --- */
+#define LOG_TIME_MSG 1
+struct log_TIME_s {
+	uint64_t t;
+};
+
+/* --- ATT - ATTITUDE --- */
+#define LOG_ATT_MSG 2
+struct log_ATT_s {
+	float roll;
+	float pitch;
+	float yaw;
+};
+
+/* --- ATSP - ATTITUDE SET POINT --- */
+#define LOG_ATSP_MSG 3
+struct log_ATSP_s {
+	float roll_sp;
+	float pitch_sp;
+	float yaw_sp;
+};
+
+/* --- IMU - IMU SENSORS --- */
+#define LOG_IMU_MSG 4
+struct log_IMU_s {
+	float acc_x;
+	float acc_y;
+	float acc_z;
+	float gyro_x;
+	float gyro_y;
+	float gyro_z;
+	float mag_x;
+	float mag_y;
+	float mag_z;
+};
+
+/* --- SENS - OTHER SENSORS --- */
+#define LOG_SENS_MSG 5
+struct log_SENS_s {
+	float baro_pres;
+	float baro_alt;
+	float baro_temp;
+	float diff_pres;
+};
+
+/* --- LPOS - LOCAL POSITION --- */
+#define LOG_LPOS_MSG 6
+struct log_LPOS_s {
+	float x;
+	float y;
+	float z;
+	float vx;
+	float vy;
+	float vz;
+	float hdg;
+	int32_t home_lat;
+	int32_t home_lon;
+	float home_alt;
+};
+
+/* --- LPSP - LOCAL POSITION SETPOINT --- */
+#define LOG_LPSP_MSG 7
+struct log_LPSP_s {
+	float x;
+	float y;
+	float z;
+	float yaw;
+};
+
+/* --- GPS - GPS POSITION --- */
+#define LOG_GPS_MSG 8
+struct log_GPS_s {
+	uint64_t gps_time;
+	uint8_t fix_type;
+	float eph;
+	float epv;
+	int32_t lat;
+	int32_t lon;
+	float alt;
+	float vel_n;
+	float vel_e;
+	float vel_d;
+	float cog;
+};
+#pragma pack(pop)
+
+/* construct list of all message formats */
+
+static const struct log_format_s log_formats[] = {
+	LOG_FORMAT(TIME, "Q", "StartTime"),
+	LOG_FORMAT(ATT, "fff", "Roll,Pitch,Yaw"),
+	LOG_FORMAT(ATSP, "fff", "RollSP,PitchSP,YawSP"),
+	LOG_FORMAT(IMU, "fffffffff", "AccX,AccY,AccZ,GyroX,GyroY,GyroZ,MagX,MagY,MagZ"),
+	LOG_FORMAT(SENS, "ffff", "BaroPres,BaroAlt,BaroTemp,DiffPres"),
+	LOG_FORMAT(LPOS, "fffffffLLf", "X,Y,Z,VX,VY,VZ,Heading,HomeLat,HomeLon,HomeAlt"),
+	LOG_FORMAT(LPSP, "ffff", "X,Y,Z,Yaw"),
+	LOG_FORMAT(GPS, "QBffLLfffff", "GPSTime,FixType,EPH,EPV,Lat,Lon,Alt,VelN,VelE,VelD,Cog"),
+};
+
+static const int log_formats_num = sizeof(log_formats) / sizeof(struct log_format_s);
+
+#endif /* SDLOG2_MESSAGES_H_ */