I'm working on embedded device with raspberry pi and HDMI screen. I want to have splash image displayed during boot, but HDMI in my Linux image is initialized after 13-14 second. I can display splash screen from uboot, this works quite well, but screen is turned black on start of Linux boot.
This is quite annoying, because I can't display anything from Linux yet, so screen is more than 10 seconds black. Many user are terrified by this behavior and keeps power cycling device in belief, that boot froze, because this isn't something, they know from consumers grade electronics.
My question then is: How can I prevent turning screen black on Linux boot? My naive idea is to send splash image to screen and then "don't touch those wires" until Linux HDMI driver is initialized and can send own splash image. I'm not sure, if there isn't some heartbeat required on HDMI interface, it would be quite complication.
I have tried to reduce HDMI init time, but this seems to be no-go. No one was able to help me with that, there are very little information about this problematic on internet, so I have to try different approach.
