anchor.diff:         (let* ((frame (or (allocate-physical-pages 1)
                            (panic "Aiee. No memory.")))
                 (data (+ +physical-map-base+ (ash frame 12))))
  -         (dotimes (i 512)
  -           (setf (sys.int::memref-unsigned-byte-64 data i) 0))
  +         (zeroize-page data)
            (insert-into-block-cache block-id data)
            data))
       (dotimes (i 255)
         (when (eql (sys.int::memref-unsigned-byte-64 cache-page (* i 2)) block-id)
           (let ((data (sys.int::memref-signed-byte-64 cache-page (1+ (* i 2)))))
  -          (dotimes (i 512)
  -            (setf (sys.int::memref-unsigned-byte-64 data i) 0))
  +          (zeroize-page data)
             (return-from zero-cached-block data))))))
   
   (defun read-cached-block (block-id)
  
positive.code: (defun address-l3-bits (address) (ldb (byte 9 30) address))
  (defun address-l2-bits (address) (ldb (byte 9 21) address))
  (defun address-l1-bits (address) (ldb (byte 9 12) address))
  
  (defun detect-paging-disk ()
    (dolist (disk (all-disks))
  
negative.code:         (let* ((frame (or (allocate-physical-pages 1)
                            (panic "Aiee. No memory.")))
                 (addr (+ +physical-map-base+ (ash frame 12))))
            (zeroize-page addr)
            (setf (page-table-entry page-table index) (logior (ash frame 12)
                                                              +page-table-present+
                                                              +page-table-write+))
  