mc146818驱动程序，已经通过实验板测试-mc146818 driver has been tested by experiment board

This file is subject to the terms and conditions of the GNU General Public License. See the file COPYING in the main directory of this archive for more details. -This file is subject to the terms and conditions of the GNU General Public License. Se

For check timing call set_rtc_mmss() 500ms used in timer interrupt. -For check timing call set_rtc_mmss() 500ms used in timer interrupt.