[REQ] Dump imgdata partition for changing bootlogo

I need a dump image of the imgdata partition. Imgdata partition contains the imges of the bootloader like the boot logo and the images you see in fastboot mode.

I made a successfull boot logo change and bootloader skining thread for the nexus 5 (hammerhead) and now I want to give support for nexus 5x (bullhead) too as it has imgdata partition just like the previous nexus 5.

Thanks in advance.