kernel crashing with jffs2 (32MB NAND Flash and 32MB SDRAM )

[venki kaps]

Thanks for the reply.
It's a new hardware i.e, ATMEL AT91SAM9G20 Board
and at the same first time we are using.

Did *this* board ever work correctly?
No.

But At mem=8M and mem=16M the Linux is coming up
but after the kernel prompt it is crashing in between.

At mem=32M the Linux is not coming up over board.
Before kernel prompt it’s crashing.

If SDRAM is problem, Linux itself is not coming up over board.
am i right?

is it u-boot problem?
i.e  number of column & row address bits and the number of banks is
set correctly to match the installed SDRAM

is it required to change u-boot or SDRAM or 2.6.27 kernel?

Could you suggest something?

Thanks & Regards,
Venkappa


On Tue, Jul 7, 2009 at 9:21 AM, Iwo Mergler<iwo at call-direct.com.au> wrote:
> venki kaps wrote:
>> Hi,
>>
>>  We are facing some memory issues with ATMEL AT91SAM9G20 Board.
>>  By changing the uboot environment variable –bootargs
>> setenv bootargs console=ttyS0,115200 root=/dev/mtdblock2 rootfstype=jffs2 mem=8M
>> mem=8M
>> mem=16M
>> mem=24M
>> mem=32M
>> On changing the value of mem variable the boards behaves in different way.
>>
>> At 8M,16M the Linux is coming up but after the kernel prompt it is
>> crashing in between.
>> At 32M-the Linux is not coming up over board. Before kernel prompt
>> it’s crashing.
>> The size of SDRAM is 32MB.but we are not able to utilize it fully.
>>
>> Is it u-boot or Kernel or jffs2 or SDRAM problem?
>>
>
> There could be many possible explanations, including electrical board faults
> (shorted address lines), bad SDRAM, unsupported SDRAM chips, etc. Is it a new
> board design? Did *this* board ever work correctly? You didn't give enough
> detail to comment on these things.
>
> As for the software side, incorrectly programming the SDRAM controller can
> cause the symptoms you described.
>
> The SDRAM controller is programmed by the bootstrap code, as U-Boot needs
> the SDRAM already operational to run.
>
> Add some code to U-Boot to print out the contents of the SDRAMC Configuration
> Register (see the data sheet). Make sure the number of column & row address
> bits and the number of banks is set correctly to match the installed SDRAM.
>
> Best regards,
>
> Iwo
>
>