hw: don't use assert in Kernel::start_thread

ref #1101

base-hw/src/core/kernel/kernel.cc

@@ -93,7 +93,7 @@ namespace Kernel
 	/**
 	 * Static kernel PD that describes core
 	 */
-	static Pd * core()
+	Pd * core()
 	{
 		/**
 		 * Core protection-domain
@@ -262,7 +262,7 @@ extern "C" void init_kernel_multiprocessor()
 		_main_thread_utcb->start_info()->init(t.id(), Genode::Native_capability());
 		t.ip = (addr_t)CORE_MAIN;;
 		t.sp = (addr_t)s + STACK_SIZE;
-		t.init(processor_pool()->processor(processor_id), core_id(), &utcb, 1);
+		t.init(processor_pool()->processor(processor_id), core(), &utcb, 1);
 
 		/* kernel initialization finished */
 		init_platform();

base-hw/src/core/kernel/processor_pool.h

@@ -25,7 +25,7 @@ namespace Kernel
 	/**
 	 * Return kernel name of core domain
 	 */
-	unsigned core_id();
+	Pd * core();
 
 	/**
 	 * Thread that consumes processor time if no other thread is available
@@ -75,7 +75,7 @@ class Kernel::Idle_thread : public Thread
 		{
 			ip = (addr_t)&_main;
 			sp = (addr_t)&_stack[STACK_SIZE];
-			init(processor, core_id(), 0, 0);
+			init(processor, core(), 0, 0);
 		}
 };
 

base-hw/src/core/kernel/thread.cc

@@ -190,8 +190,7 @@ Thread::Thread(unsigned const priority, char const * const label)
 }
 
 
-void
-Thread::init(Processor * const processor, unsigned const pd_id_arg,
+void Thread::init(Processor * const processor, Pd * const pd,
              Native_utcb * const utcb_phys, bool const start)
 {
 	assert(_state == AWAITS_START)
@@ -201,8 +200,7 @@ Thread::init(Processor * const processor, unsigned const pd_id_arg,
 	_utcb_phys = utcb_phys;
 
 	/* join protection domain */
-	_pd = Pd::pool()->object(pd_id_arg);
-	assert(_pd);
+	_pd = pd;
 	addr_t const tlb = _pd->tlb()->base();
 	User_context::init_thread(tlb, pd_id());
 
@@ -356,26 +354,33 @@ void Thread::_call_start_thread()
 		user_arg_0(0);
 		return;
 	}
-	/* lookup targeted thread */
+	/* lookup thread */
 	unsigned const thread_id = user_arg_1();
 	Thread * const thread = Thread::pool()->object(thread_id);
 	if (!thread) {
-		PWRN("unknown thread");
+		PWRN("failed to lookup  thread");
 		user_arg_0(0);
 		return;
 	}
-	/* lookup targeted processor */
+	/* lookup processor */
 	unsigned const processor_id = user_arg_2();
 	Processor * const processor = processor_pool()->processor(processor_id);
 	if (!processor) {
-		PWRN("unknown processor");
+		PWRN("failed to lookup  processor");
+		user_arg_0(0);
+		return;
+	}
+	/* lookup domain */
+	unsigned const pd_id = user_arg_3();
+	Pd * const pd = Pd::pool()->object(pd_id);
+	if (!pd) {
+		PWRN("failed to lookup domain");
 		user_arg_0(0);
 		return;
 	}
 	/* start thread */
-	unsigned const pd_id = user_arg_3();
 	Native_utcb * const utcb = (Native_utcb *)user_arg_4();
-	thread->init(processor, pd_id, utcb, 1);
+	thread->init(processor, pd, utcb, 1);
 	user_arg_0((Call_ret)thread->_pd->tlb());
 }
 

base-hw/src/core/kernel/thread.h

@@ -301,12 +301,12 @@ class Kernel::Thread
 		/**
 		 * Prepare thread to get scheduled the first time
 		 *
-		 * \param processor  kernel object of targeted processor
-		 * \param pd_id      kernel name of target protection domain
+		 * \param processor  targeted processor
+		 * \param pd         targeted domain
 		 * \param utcb       core local pointer to userland thread-context
 		 * \param start      wether to start executing the thread
 		 */
-		void init(Processor * const processor, unsigned const pd_id,
+		void init(Processor * const processor, Pd * const pd,
 		          Native_utcb * const utcb, bool const start);