[PATCH 12/12] [POWERPC] 85xx: Add support for relocatble kernel (and booting at non-zero)

[Kumar Gala]

> What happens if CONFIG_KERNEL_START != CONFIG_PAGE_OFFSET and the
> kernel is loaded at some address != CONFIG_PHYSICAL_START?

Assuming its not a CONFIG_RELOCATABLE kernel than bad things.  Is  
there some concern you have here?

> Are we sure that ARCH_PFN_OFFSET only gets applied to normal memory
> pages, not any I/O?

correct.  ioremap uses map_page which isn't effected by ARCH_PFN_OFFSET

>  What happens to /dev/mem when ARCH_PFN_OFFSET != 0?

it behaves the same.  You provide a physical address and it provides  
access to it.  (so you could access memory you aren't suppose to)

- k