Spinlock save cpu flags

kernel/amd64/debug.c

@@ -33,6 +33,8 @@ static void debug_serial_write (char x) {
  * Formatted printing to serial. serial_lock ensures that all prints are atomic.
  */
 void debugprintf (const char* fmt, ...) {
+  uint64_t f1;
+
   if (!debug_is_init)
     return;
 
@@ -48,14 +50,14 @@ void debugprintf (const char* fmt, ...) {
 
   const char* p = buffer;
 
-  spin_lock (&serial_lock);
+  spin_lock (&serial_lock, &f1);
 
   while (*p) {
     debug_serial_write (*p);
     p++;
   }
 
-  spin_unlock (&serial_lock);
+  spin_unlock (&serial_lock, f1);
 }
 
 /* Initialize serial */