Thanks Guys. My problem solved. As you stated, SD Card was the problem.|
I bought a Sandisk 8GB class 10 Micro SD Card (tested it with h2testw for fake capacity or speed), wrote bananian image on it, turned on Banana pi and Viola! Red led, then Green led, then green blinking and after few secs, another blue/magneta led turned on too.
I also bought a USB to Serial ttl converter (cp2102 chip, Extra cheap, from SiLabs, only $3 and compatible with win/mac/linux/android) for debugging purposes, checked pins voltages with multimeter (tx/rx should be 3.3v) and connected it to j11 pins of banana pi (refer to gpio layouts), and viola again: i can now see whats happening even before kernel launch. Heavily recommend this.