I’ve collected a few tools for custom bootsplash images, in first read this shortly how-to:

1. Download it from here
2. All files must be extracted in the same folder
3. Open your favorite graphic program and create a 640×480 bitmap image (.bmp), rename it to logo.bmp
4. Start rsbbmp.exe located in the folder, and select logo.bmp file, next step – convert all
5. Now, you need to install SdkCerts.cab on your device
6. Final step – start write_logo.bat and follow the instructions

Well done, you have a new bootsplash screen 🙂