circuit breaker: move to cpp, all platforms use the same file

src/modules/systemlib/circuit_breaker.cpp

@@ -0,0 +1,56 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2014 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.
+ *
+ ****************************************************************************/
+
+/*
+ * @file circuit_breaker.c
+ *
+ * Circuit breaker parameters.
+ * Analog to real aviation circuit breakers these parameters
+ * allow to disable subsystems. They are not supported as standard
+ * operation procedure and are only provided for development purposes.
+ * To ensure they are not activated accidentally, the associated
+ * parameter needs to set to the key (magic).
+ */
+
+#include <px4.h>
+#include <systemlib/circuit_breaker.h>
+
+bool circuit_breaker_enabled(const char* breaker, int32_t magic)
+{
+	int32_t val;
+	/* (void)param_get(param_find(breaker), &val); */
+	(void)PX4_PARAM_GET_NAME(breaker, &val);
+
+	return (val == magic);
+}
+