fix make for a21, PIDs are always ints, linter things

kernel/thread/thread.h

@@ -28,14 +28,12 @@ class Thread {
 	/*! \brief pointer to the next element of the readylist
 	 */
 	Thread* queue_link;
-
 	friend class Queue<Thread>;
 	friend class Semaphore;
 	/*! \brief Memory reserved for this threads stack
 	 */
 	alignas(16) char reserved_stack_space[STACK_SIZE];
 
-   protected:
 	/*! \brief Context of the thread, used for saving and restoring the register
 	 * values when context switching.
 	 */
@@ -56,17 +54,25 @@ class Thread {
 	 *  \param param1 Thread to be started
 	 *  \param param2 Second parameter (will be used later)
 	 *  \param param3 Third parameter (will be used later)
+	 *
 	 */
 	static void kickoff(uintptr_t param1, uintptr_t param2, uintptr_t param3);
 
    public:
 	/*! \brief Unique thread id */
-	const size_t id;
+	const int id;
 
 	/*! \brief Marker for a dying thread
 	 */
 	volatile bool kill_flag;
 
+	// Naively moving or copying esp. the (user) stack of a thread would be a
+	// bad idea:
+	Thread(const Thread&) = delete;
+	Thread(Thread&&) = delete;
+	Thread& operator=(const Thread&) = delete;
+	Thread& operator=(Thread&&) = delete;
+
 	/*! \brief Constructor
 	 *  Initializes the context using \ref prepareContext with the thread's
 	 * stack space.