AM3352移植FATFs的问题

hi，

    我移植了一个FatFs R0.13版本的到StarterWare软件上，参照官方的Demo。以此来挂载NAND和USB U盘，现在在移植挂载Nand时需要修改FatFs的如下配置

#define FF_MIN_SS		512
#define FF_MAX_SS		512 // NAND: 2048
/* This set of options configures the range of sector size to be supported. (512,
/  1024, 2048 or 4096) Always set both 512 for most systems, generic memory card and
/  harddisk. But a larger value may be required for on-board flash memory and some
/  type of optical media. When FF_MAX_SS is larger than FF_MIN_SS, FatFs is configured
/  for variable sector size mode and disk_ioctl() function needs to implement
/  GET_SECTOR_SIZE command. */

其中根据需求在设置扇区大小为2048来适配Nand的page大小时，发现设置为2048后加载不了U盘，请教一下此种情况是啥问题？