Bin file instead of wic file

[gopikabg]

Hi everyone,
I am using sama5d27 som1 board and yocto project. I have build the images and flashed the wic file it and found it working. I need image in bin format so that i can dump it to emmc using another tool.
Modified the conf file IMAGE_FSTYPES += "bin"
But not working
Could someone help me on this.
Thanks in anticipation.