针对友善之臂4412开发板裸机下操作LCD显示驱动，注：Lcd的背光默认没有开启，可以通过先加载linux内核来开启背光，然后按reset键重启进入u-boot来运行自己的程序；-Note 4412: Lcd s default backlight is not turned on, you can first load the linux kernel to open the backlight, and then press the reset key to restart into the u-boot to run your own program