屏蔽内核启动打印

修改kernel/printk.c文件，找到

/*
 * Call the console drivers on a range of log_buf
 */
static void __call_console_drivers(unsigned start, unsigned end)
{
	struct console *con;
	for_each_console(con) {
		if (exclusive_console && con != exclusive_console)
			continue;
//if ((con->flags & CON_ENABLED) && con->write &&
//				(cpu_online(smp_processor_id()) ||
//				(con->flags & CON_ANYTIME)))
//			con->write(con, &LOG_BUF(start), end - start);
	}
}

将最后四行注释掉。