o Now CONFIG_PHYSICAL_START is being replaced with CONFIG_PHYSICAL_ALIGN.
  Hardcoding the kernel physical start value creates a problem in relocatable
  kernel context due to boot loader limitations. For ex, if somebody
  compiles a relocatable kernel to be run from address 4MB, but this kernel
  will run from location 1MB as grub loads the kernel at physical address
  1MB. Kernel thinks that I am a relocatable kernel and I should run from
  the address I have been loaded at. So somebody wanting to run kernel
  from 4MB alignment location (for improved performance regions) can't do
  that.

o Hence, Eric proposed that probably CONFIG_PHYSICAL_ALIGN will make
  more sense in relocatable kernel context. At run time kernel will move
  itself to a physical addr location which meets user specified alignment
  restrictions.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>