How can I support 2GB of memory in Linux kernel on 440SPe

Hi,

I need to support 2GB of memory on a custom 440SPe board.

I see to support 1GB of memory on the 440SPe yucca board the following
configuration changes were done.

#
# Advanced setup
#

CONFIG_ADVANCED_OPTIONS=y
CONFIG_HIGHMEM_START=0xfe000000
CONFIG_LOWMEM_SIZE_BOOL=y
CONFIG_LOWMEM_SIZE=0x40000000
CONFIG_KERNEL_START_BOOL=y
CONFIG_KERNEL_START=0xa0000000
# CONFIG_TASK_SIZE_BOOL is not set
CONFIG_TASK_SIZE=0x80000000
# CONFIG_CONSISTENT_START_BOOL is not set CONFIG_CONSISTENT_START=0xff100000
# CONFIG_CONSISTENT_SIZE_BOOL is not set
CONFIG_CONSISTENT_SIZE=0x00200000 # CONFIG_BOOT_LOAD_BOOL is not set
CONFIG_BOOT_LOAD=0x01000000

It looks like the only thing I would need to do is modify the
following for 2GB support.

CONFIG_LOWMEM_SIZE=0x80000000
and
CONFIG_KERNEL_START=0x60000000

But this does not work. It almost does, but right after I get to the
Linux prompt, this system panics. If I scale back to one 1GB
everything works great.

Any ideas?

Thank You,

Vincitore