Hi!
My goal is to create a Debian system with a self-built kernel, which also supports the Display 8HD with touchscreen.
To test the hardware and the wiring, I used a ready-made Debian image (rock-4se_debian_bullseye_kde_b38.img with Linux 5.10.110-18-rockchip) and installed the DT-Overlay rock-4se-radxa-display-8hd with rsetup. Touchscreen and display (8HD and HDMI) are working.
In the Radxa kernel GIT (https://github.com/radxa/kernel.git) I have now searched for the sources for the kernel used in the image, but couldn’t find it. I have used the source with the tag 5.10.131-2-rockchip for my test instead. I extracted the kernel configuration from the image (/proc/config.gz). As a basis for the Device Tree configuration I took the file rk3399-rock-pi-4a.dts and the extension from the overlay rock-4se-radxa-display-8hd.dts on the repository https://github.com/radxa/overlays.git). I had to change tags like dsi or dsi1 to mipi_dsi and mipi_dsi1 because the original identifiers did not exist.
The kernel created in this way starts, but the display does not work. I can’t get a picture either via the 8HD display or via HDMI. What am I doing wrong? What else do I need to do? Has anyone already managed this? Since I have to integrate my own drivers, I can’t avoid creating my own kernel.