[U-Boot] Not able load u-boot from flash to ddr

[Stefan Roese]

On 05/07/2013 05:53 PM, sadashiva reddy wrote:
> I working on PPC440Gx processor.
> 
> I set the macro CONFIG_SYS_TEXT_BASE to 0xFFFC0000. So, the u-boot.bin is
> created with 256KB file size.
> 
> This file I am loading to flash using with BDI2000 emulator.
> 
> But after loading to flash the bootloader is not copying the file from
> flash to DDR location.
> This we confirmed by probing the data lines and address lines of flash and
> SDRAM. Nothing was toggling when we probe the lines using CRO.

CRO?

You should at least see one access to the FLASH location 0xffff.fffc.
This is the reset-vector, where the CPU starts loading the first code
(usually a jump to another location).

> But when we program vxWorks bootloader i.e bootrom.bin where the TEXT_ADDR
> is 0xFFE00000.
> The bootrom.bin file is created with 2MB file size. When we load this file
> to flash we are able to the see bootloader is copying to DDR location while
> probing.
> 
> What could be the problem in u-boot case why it is not copying to DDR?

This could have many, many reasons. Did you actually *port* U-Boot to
your board? Change the settings for the SDRAM controller, UART,
chip-select setup etc. All this has to be done correctly, before U-Boot
can run full to the prompt.

But again, you should at least see some accesses to the FLASH, when the
CPU starts fetching and executing the first instructions. Later on SDRAM
will get initialized and then U-Boot will start using the SDRAM. So
accesses to SDRAM will come much later. But the serial console output
from U-Boot starts pretty soon. So, with a functional U-Boot port you
will see a few lines on the console before the SDRAM is initialized.

So again, please make sure that you have configured/changed/ported your
U-Boot port correctly for your custom 440GX board. You might want to
start with some other 440GX boards.

Hope this helps a bit.

Cheers,
Stefan