Add kernel logging task

- Enable creating kernel tasks
- Create kernel task that disables immediate-mode logging and prints
  logs to the console forever

src/kernel/log.cpp

@@ -28,6 +28,31 @@ output_log(log::area_t area, log::level severity, const char *message)
 	cons->set_color();
 }
 
+void
+logger_task()
+{
+	uint8_t buffer[257];
+	auto *ent = reinterpret_cast<log::logger::entry *>(buffer);
+	auto *cons = console::get();
+
+	g_logger.set_immediate(nullptr);
+	log::info(logs::task, "Starting kernel logger task");
+
+	while (true) {
+		__asm__ ("cli");
+		if(g_logger.get_entry(buffer, sizeof(buffer))) {
+			buffer[ent->bytes] = 0;
+			cons->set_color(level_colors[static_cast<int>(ent->severity)]);
+			cons->printf("%9s %8s: %s\n",
+				g_logger.area_name(ent->area),
+				g_logger.level_name(ent->severity),
+				ent->message);
+			cons->set_color();
+		}
+		__asm__ ("sti");
+	}
+}
+
 void init()
 {
 	new (&g_logger) log::logger(log_buffer, sizeof(log_buffer));