add logging + restore preemption

c_os/devices/PIT.h

@@ -12,6 +12,7 @@
 #define __PIT_include__
 
 #include "kernel/interrupts/ISR.h"
+#include "user/lib/Logger.h"
 
 class PIT : public ISR {
 private:
@@ -20,13 +21,15 @@ private:
     enum { time_base = 838 }; /* ns */
     int timer_interval;
 
+    Logger log;
+
     char indicator[4] = {'|', '/', '-', '\\'};
     unsigned int indicator_pos = 0;
     unsigned long last_indicator_refresh = 0;
 
 public:
     // Zeitgeber initialisieren.
-    PIT(int us) {
+    PIT(int us) : log("PIT") {
         this->interval(us);
     }