HAL_PX4: fixes for new Scheduler API

libraries/AP_HAL_PX4/HAL_PX4_Class.cpp

@@ -82,6 +82,7 @@ static int main_loop(int argc, char **argv)
     hal.rcout->init(NULL);
 
     setup();
+    hal.scheduler->system_initialized();
 
     while (true) {
 		loop();

libraries/AP_HAL_PX4/Scheduler.cpp

@@ -187,4 +187,20 @@ void PX4Scheduler::panic(const prog_char_t *errormsg) {
     exit(1);
 }
 
+bool PX4Scheduler::in_timerprocess() {
+    return _in_timer_proc;
+}
+
+bool PX4Scheduler::system_initializing() {
+    return !_initialized;
+}
+
+void PX4Scheduler::system_initialized() {
+    if (_initialized) {
+        panic(PSTR("PANIC: scheduler::system_initialized called"
+                   "more than once"));
+    }
+    _initialized = true;
+}
+
 #endif

libraries/AP_HAL_PX4/Scheduler.h

@@ -33,7 +33,12 @@ public:
     void     panic(const prog_char_t *errormsg);
     bool     interrupts_are_blocked(void) { return _nested_atomic_ctr != 0; }
 
+    bool     in_timerprocess();
+    bool     system_initializing();
+    void     system_initialized();
+
 private:
+    bool _initialized;
     static uint8_t _nested_atomic_ctr;
     AP_HAL::Proc _delay_cb;
     uint16_t _min_delay_cb_ms;