Show splash screen above Cage

[The-Man11]

Hi everyone, much love from Italy!
I am currently building an embedded system for a car infotainment, and decided to opt for Cage, since it seemed the most sensible choice.

I tried (with no success, and not much experience either) to keep the Plymouth (or any other splash screen) active after starting Cage, but to me it seems not possible. Not sure if it is even supported by hardware/software implementations.

Let me know if there could be any workaround or solution to this, since i would really need to keep up that splash screen to hide some of the loading that is happening inside of the application. (And i think there might be quite a lot of use cases for this, mostly for embedded systems).

Thanks,
Man

[joggee-fr]

I don't know if it is Cage or elsewhere, but I think the "framebuffer" (DRM devce) is cleared at Cage initialization. Are you not able to show a kind of splash screen directly in the started application?

[emersion]

I think that'd be a very nice feature.

Yeah, on startup cage performs a modeset with a black buffer. We'd need to avoid doing that modeset for outputs which are already turned on and if we can page-flip with our own swapchain, then delay the render loop until the client commits its first buffer.

[The-Man11]

I don't know if it is Cage or elsewhere, but I think the "framebuffer" (DRM devce) is cleared at Cage initialization. Are you not able to show a kind of splash screen directly in the started application?

Hi Jonathan!
Yes well, i implemented that splash screen on the application as well since i could not find a solution using Cage, but it is sub-optimal. The Plymouth splash disappears, then there is a black screen, followed by a white screen briefly, and that is not really something I would want on my finished product (bear in mind that right now its only a personal project, so it doesnt really matter that much), but i would prefer something more polished and OEM-like.

[The-Man11]

I think that'd be a very nice feature.

Yeah, on startup cage performs a modeset with a black buffer. We'd need to avoid doing that modeset for outputs which are already turned on and if we can page-flip with our own swapchain, then delay the render loop until the client commits its first buffer.

Exactly Simon! It would be very cool, and not limited to this case, but as i said it could be used for other purposes, like terminals, vending machines etc.

I am not sure about what you wrote tho, i didn't really understand much of it ahahah. But correct me if i'm wrong, in simple terms what you are saying is that we should try to "disable" the video output until the first frame of the app renders, right?

My goal as i said is to have a clean startup.
Power Button > Splash Screen (with no flickers, black or white screens) > Loaded App (which in this case is React Carplay by Rhys Morgan)

I modified it a bit but still is not as nice as i would like the final project to look like...

[ZirixCZ]

Does the client immediately commit its buffer @The-Man11 ? Are you trying to display splash until the client commits, or are you trying to hide the client's loading state. You mentioned "then there is a black screen, followed by a white screen briefly,". If cage waited for the client's frame buffer commit and the client committed with a white screen, it would be displayed regardless. You also asked for a workaround. This is what I though of. Use Plymouth's Fade-In option. When cage loads spawn your app and immediately the splash screen again. Once your app loads, kill the splash screen. Post demonstrative videos if you try any workarounds, I'm curious of how it'd look like.