release 0.0.1 of fsfw added as a core

fsfw/osal/FreeRTOS/Timekeeper.cpp

@@ -0,0 +1,41 @@
+#include "Timekeeper.h"
+
+#include "FreeRTOSConfig.h"
+
+Timekeeper * Timekeeper::myinstance = nullptr;
+
+Timekeeper::Timekeeper() : offset( { 0, 0 } ) {}
+
+Timekeeper::~Timekeeper() {}
+
+const timeval& Timekeeper::getOffset() const {
+	return offset;
+}
+
+Timekeeper* Timekeeper::instance() {
+	if (myinstance == nullptr) {
+		myinstance = new Timekeeper();
+	}
+	return myinstance;
+}
+
+void Timekeeper::setOffset(const timeval& offset) {
+	this->offset = offset;
+}
+
+timeval Timekeeper::ticksToTimeval(TickType_t ticks) {
+	timeval uptime;
+	uptime.tv_sec = ticks / configTICK_RATE_HZ;
+
+	//TODO explain, think about overflow
+	uint32_t subsecondTicks = ticks % configTICK_RATE_HZ;
+	uint64_t usecondTicks = subsecondTicks * 1000000;
+
+	uptime.tv_usec = usecondTicks / configTICK_RATE_HZ;
+
+	return uptime;
+}
+
+TickType_t Timekeeper::getTicks() {
+    return xTaskGetTickCount();
+}