sched: implement user-mode task and thread creation

sched/task.c

@@ -145,7 +145,7 @@ kern_status_t setup_idle_task(void)
 
 	idle_thread->tr_id = 0;
 	idle_thread->tr_parent = __idle_task;
-	thread_init(idle_thread, (uintptr_t)idle);
+	thread_init_kernel(idle_thread, (uintptr_t)idle);
 
 	queue_push_back(&__idle_task->t_threads, &idle_thread->tr_parent_entry);
 
@@ -170,6 +170,50 @@ struct task *task_alloc(void)
 	return t;
 }
 
+struct task *task_create(struct task *parent, const char *name)
+{
+	struct task *task = task_alloc();
+	if (!task) {
+		return NULL;
+	}
+
+	pmap_t pmap = pmap_create();
+	if (pmap == PMAP_INVALID) {
+		object_unref(&task->t_base);
+		return NULL;
+	}
+
+	task->t_id = pid_alloc();
+	task->t_pmap = pmap;
+	vm_region_create(
+		NULL,
+		"root",
+		VM_USER_BASE,
+		VM_USER_LIMIT - VM_USER_BASE,
+		VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXEC | VM_PROT_USER,
+		&task->t_address_space);
+
+	task->t_address_space->vr_pmap = pmap;
+	task->t_state = TASK_STOPPED;
+	task->t_handles = handle_table_create();
+
+	if (name) {
+		strncpy(task->t_name, name, sizeof task->t_name);
+		task->t_name[sizeof task->t_name - 1] = '\0';
+	}
+
+	unsigned long flags;
+	task_lock_irqsave(parent, &flags);
+	queue_push_back(&parent->t_children, &task->t_child_entry);
+	task_unlock_irqrestore(parent, flags);
+
+	spin_lock_irqsave(&task_list_lock, &flags);
+	task_list_insert(&task_list, task);
+	spin_unlock_irqrestore(&task_list_lock, flags);
+
+	return task;
+}
+
 struct task *task_from_pid(unsigned int pid)
 {
 	unsigned long flags;
@@ -179,6 +223,20 @@ struct task *task_from_pid(unsigned int pid)
 	return t;
 }
 
+struct thread *task_create_thread(struct task *parent)
+{
+	struct thread *thread = thread_alloc();
+	thread->tr_id = parent->t_next_thread_id++;
+	thread->tr_prio = PRIO_NORMAL;
+	thread->tr_state = THREAD_STOPPED;
+	thread->tr_parent = parent;
+	thread->tr_quantum_target = default_quantum();
+
+	queue_push_back(&parent->t_threads, &thread->tr_parent_entry);
+
+	return thread;
+}
+
 struct task *current_task(void)
 {
 	struct thread *thr = current_thread();