[ros-diffs] [fireball] 32463: - Save original value of the free descriptor we're using to alloc early pages from. - Fix handling of PFN database pages inside PFN: largest free descriptor does not always end with the highest usable physical page (MmPageArraySize). This removes the need for a "good hack" introduced in revision 32405. As a result, the memory above the largest free descriptor (if it exists) is now correctly marked in the PFN database as free and added to the unzeroed list.