Hi Andi,

In order to port kdump to x86_64, we need to have the 
memmap= kernel command line option available. This is so 
that the dump-capture kernel can be booted with a custom 
memory map.

The attached patch adds the memmap= functionality to the 
x86_64 kernel. It is against 2.6.12-rc2-mm3. I have done 
some amount of testing and it is working fine.

Could you kindly review this patch and let me know your 
thoughts on it.

Thanks and Regards,
Hari