Minimal Yocto image requirements to show custom logo

Hello everyone,

I have created a custom Yocto image (using BSP 5 and Yocto dunfell with the latest versions of everything) for my iMX8DX 1.0D based on Reference Minimal Image with small changes in u-boot, kernel and device tree overlays just to learn how everything works. Kernel modification includes the addition of a custom logo. Device tree overlays modification includes the addition of my parallel RGB display I want to use.

The description of the Reference Minimal Image says it is about booting without any graphics. Therefore, I presume it is good time now to add something to see at least my custom kernel logo.
Could you please advise me what should I add to my custom, yet minimal, image to achieve this? For a start, I want to make sure my display dtbo file is correct and seeing the logo is a good verification for me.

I have checked the Reference Multimedia Image, it is too overpowered for me. Right now, I do not need Qt5 or GStreamer or anything like this. The best start will probably be the implementation of modified I guess?

Thank you in advance for any tips/advices.
Best regards,

You might just as well build that reference multimedia image and see if things go. Might be easier working backward than forward?

Hi @DaveM,

thank you for your comment. Honestly, I thought that moving forward from a simple image to a difficult one could be better. I just have to learn everything about Yocto stuff and the minimal image was a good study material.
There is also a problem with my RGB display - Iris board sends data in a specific order, but my display requires different data order so a special “converter” board had to be created. When I was writing my post, I was ensured everything around the “converter” board works.
When I tried my custom simple image just to test if it boots at all and explore the communication using Putty, I expected that I will see something on the display. But I saw nothing so I automatically presumed that I am missing something in my custom image (or my dtbo is bad).

As it turned out, there was a hardware problem with that converter board. Now I can see the console output on the display with my simple image. I am going to explore the multimedia image and hopefully, I will make it work.

Best regards,

Hey @John1, glad you got something out of it! We also have our own display that wasn’t supported out of the box so made the appropriate dtb modifications to get it going. I went with the multimedia image and got lucky really. And now I’m with you looking at the minimal image and experimenting how to add my own layers, change the partitioning scheme, use the 485 functionality, etc. Fun stuff!