Could you run "make bf527-ezkit" with our standard release code, as described in http://docs.blackfin.uclinux.org/doku.php?id=bootloaders:u-boot:compiling, and update us the result?
Note if you encountered some issue after making changes of your own, please be back to us with patches that describing your changes, along with a brief description of your ultimate goal so we can put effort on your issue support.