此代码为全志R16(A33)平台，nand驱动的代码，R16源码在init.rc阶段支持nand模块加载，但需要把生成的nand.ko放入ramdisk.img中，并且能调用insmod命令插入nand模块，这样才可正常启动。-this nand driver code is based on R16 soc of allwinner. if you develop board want to support nand flash ,you can put nand.ko in RAMDISK.