Beaglebone Yocto with external flash booting

Hi all,

I have build yocto image in .wic format for beaglebone black. And it successfully boot from onboard NAND flash and sdcard. Now I want to do booting from external flash connected on SPI interface. I am unable to understand how to program .wic image in external flash or what are are the other image format required for programming and booting of external flash.

Thanks & Regards,

Nikhil Muley