I found it via Google. Go to MSM tap F8, check boot a or boot b (Google the fastboot slot command if you don't know which slot your phone is in), put "oneplus" as the password then click on Read Back and it'll wait until you plug in your device in EDL mode. Once you do, you'll find the boot.img file in your C:/ folder. That's it.
F.17 is the latest. Look at post #140 on page 7 for the stock LE2115.F.17 boot.img.
Sir please provide boot.img for LE2011_11_F17. We are desperately waiting for the file.
Please don't quote me for a model I do not own. If you are "desperate" you can extract it yourself. I already posted how to some posts above yours. Good luck.
LE2115 Global F.18 stock boot.img attached....and @Z-Blade, there's no way to stuff up, the only thing that can happen is missing the EDL window which you can totally avoid just by tapping on ReadBack Mode before pluggin in the phone in EDL mode. Enjoy.
Thank u !!!!