My BeBook e-book reader is just rebranded Jinke and as such there is quite a lot possibility of customization. I will save discussing all different versions of firmware for some other post, this time I will just discuss changing logo.
Jinke decided to make it's LogoMaker available for all owners to change both boot and shutdown images.
Preparing is easy. Just create two bitmaps (one for boot and one for shutdown) and save them as .bmp images. Start LogoMaker and give path to those two images just created and you will get logo.bin and logo.md5. Those two files are all you need.
Once both SD card and logo files are in place you can go into Settings. There you will see "Update boot and shutdown logo" option available. Once selected, update will happen very fast and device will be turned off.
Once you turn device back on you will be able to enjoy your new startup screen.