Hi 2009/8/16 alfred steele <alfred.jaq...@gmail.com>: > 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.
That depends on how your dram_init looks like, none of the i.MX31 dram_init's I've looked at handles more than one DRAM bank. > > 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) Not that I've been working with multiple banks myself but if you have 2 banks then my guess is that you have to supply the start address and size of each of the banks. > What else does the uboot need to convey to the kernel. > I am using Freescale MX31 board. > Any hints/clues? You need to setup the SDRAM controller in i.MX31 to reflect your actual DRAM configuration. It also depends on if you have one 256M DRAM or two 128M. /Magnus _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
