[U-Boot] Incorrect board init with 256M RAM on MX31

[alfred steele]

Hi All,

When i use 128M  in my board configuration and pass the same to he
kernel using bd_info , the linux kernel just boots up fine.  But when
i change the config to put 256M which is the actual physical  DDR size
on our board,
the userspace crashes because of a "unhandled page fault"  via  Unable
to handle kernel NULL pointer dereference".
First off, perhaps the U-boot is not initializing the memory properly.
 Although i thought, the board specific "dram_init" does it with the
correct config params picked up from the board config file.

I change the following in the board specific config:
#define CONFIG_NR_DRAM_BANKS    2
#define PHYS_SDRAM_1        CSD0_BASE
#define PHYS_SDRAM_1_SIZE   (256 * 1024 * 1024)

What else does the uboot  need to convey to the kernel.
I am using Freescale MX31 board.
Any hints/clues?
Thanks in advance for your help.
-Alfred.