There's multiple ways to do it, depending on what you have running on your board. If you don't have anything running and just have JTAG connection, then you can write a small program using whatever IDE and JTAG connection you're using to develop/debug and burn the fuses that way. If you have Linux running on it, see this discussion (and attached file in one of the postings) on the Freescale Forums:http://forums.freescale.com/t5/i-MX-Microprocessors/i-MX25-HAB-secure-boot-question/td-p/57853