How to write custom firmware on st-25i

Dear supporter i have few qty of sony ericson ST-25i ,,,to which i want to write custom firmware ,,,although i have write so many custom firmware on HTC,,,but dont have any idea to write custom firmware on sony base mobile ,,,,If anybody can tell and guide me along with download link ,,,or atleast any basic idea,,,i will be realy apretiated ,,,,



awating for kind replies,,

via Welcome to gsm-tips http://ift.tt/1uRQuOA