The solution works when I use mx53_loco bsp.
Modify u-boot and kernel, keep the same. Then you may find you can't login into the system regardless of whatever you input after freescale login:
It confused me for a long time.
If you also met this problem,try to check the iomux-mx53.h(linux/arch/arm/plat-mxc/include/mach/).
#define _MX53_PAD_PATA_DIOW__UART1_TXD_MUX IOMUX_PAD(the fourth argument 0x878 should be changed to 0x0)
I think this is a small bug in header files.