(defun simplified-beginning-of-buffer ()
  "Move point to the beginning of the buffer;
   leave mark at previous position."
  (interactive)
  (setq this-position-of-cursor (point))
  (push-mark)
  (goto-char (point-min)))
 
(local-set-key "\M-<" 'simplified-beginning-of-buffer)
 
(defun return-previous-position ()
  (interactive)
  (goto-char this-position-of-cursor))
 
(local-set-key "\C-x\C-x" 'return-previous-position)