Kernel Zero Page Mapping

[Nathan Slingerland]

I am attempting to create a region of memory that can be recovered after
a warm reboot. I grab the top 4 MB of physical memory in start_kernel()
after paging_init() is called, setting kernel-wide address variables to
point to
this region of memory. I have eliminated all of the memset(address, 0,
extent) that I can find, but I have a problem
in that linux maps in a zero-filled page for all pages not found in the
page table (which my warm data will not be).
 In summary, I want to be able to directly map in some of the raw memory
contents after a warm reboot. Where is this zero mapping associated with
a page?

Any ideas or help on this would be _greatly_ appreciated!

Thankyou for taking the time to read this.

-Nathan