From ca3f6f59f907f659a6f645a4634a34ec6eae9f9c Mon Sep 17 00:00:00 2001
From: Daniel Agar <daniel@agar.ca>
Date: Thu, 9 Dec 2021 12:50:20 -0500
Subject: [PATCH] dataman: add SYS_DM_BACKEND parameter

---
 .gitignore                       |  4 ---
 ROMFS/px4fmu_common/init.d/rcS   | 11 +++++++-
 src/modules/dataman/parameters.c | 44 ++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 5 deletions(-)
 create mode 100644 src/modules/dataman/parameters.c

diff --git a/.gitignore b/.gitignore
index 5d37a8e4e2..f1945d12ed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -105,8 +105,4 @@ src/lib/version/build_git_version.h
 src/modules/simulator/simulator_config.h
 src/systemcmds/topic_listener/listener_generated.cpp
 
-# SITL
-dataman
-eeprom/
-
 !src/drivers/distance_sensor/broadcom/afbrs50/Lib/*
diff --git a/ROMFS/px4fmu_common/init.d/rcS b/ROMFS/px4fmu_common/init.d/rcS
index 489461ae8a..2b57ac7a6b 100644
--- a/ROMFS/px4fmu_common/init.d/rcS
+++ b/ROMFS/px4fmu_common/init.d/rcS
@@ -235,7 +235,16 @@ else
 	# Waypoint storage.
 	# REBOOTWORK this needs to start in parallel.
 	#
-	dataman start
+	if param compare SYS_DM_BACKEND 1
+	then
+		dataman start -r
+	else
+		if param compare SYS_DM_BACKEND 0
+		then
+			# dataman start default
+			dataman start
+		fi
+	fi
 
 	#
 	# Start the socket communication send_event handler.
diff --git a/src/modules/dataman/parameters.c b/src/modules/dataman/parameters.c
new file mode 100644
index 0000000000..06fa34564e
--- /dev/null
+++ b/src/modules/dataman/parameters.c
@@ -0,0 +1,44 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2021 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.
+ *
+ ****************************************************************************/
+
+/**
+ * Dataman storage backend
+ *
+ * @group System
+ * @value -1 Disabled
+ * @value 0 default (SD card)
+ * @value 1 RAM (not persistent)
+ * @boolean
+ * @reboot_required true
+ */
+PARAM_DEFINE_INT32(SYS_DM_BACKEND, 0);