custom splash screen

Sorry if this has already been addressed somewhere else, but I am having trouble flashing these to my thunderbolt as a splash screen.

I have the image on the root of my sd. It is named PG05IMG.zip. When I boot into bootloader it does the usual quick list of things like checking/loading/parsing PG05IMG.zip, but it never gives me the option to update.

Thanks in advance
 
My first post, need links to figure out how bootanimations and splash screens. I'm a graphic artist animator. Fun!!!
 
Wow, thanks, upstreammiami! I came here trying to find the instructions to compile one (I did it once with my Inc, but that was 18 months ago) and instead found every one that I was thinking about making available for download, along with one that hadn't occurred to me that'll probably be my primary (the simple Google one).