If you want to backup your old bootloader (before flashing new), then it's really easy if you happen to have FAT/FAT32 usb stick/drive and it's recognized by firmware. Just open hidden admin page, type exactly the following
Code:
(cat /dev/mtd/0 > /tmp/harddisk/cfe.bin &)
and then press Refresh button (do not press Enter). This should create 256k cfe.bin file on the flash drive.
P.S. If you've hardware_version other than indicated above - drop me a mail or PM before updating bootloader, I would like to check existing bootloader image first.
P.P.S. FTP server should be enabled for your usb drive to be mounted (accessible) by router.