Hi everyone:
I'm trying to update my two applications to the current 6.12 branch from https://github.com/raspberrypi/linux.
However, even after a clean start, I'm having trouble generating a simple image (using Buildroot 2025.02.3, starting from scratch) that can run kmscube or glmark2 just for testing purposes. I’d appreciate your help in determining the correct selections for kernel configuration, drivers, packages, and config.txt settings for use with CM4 devices at their current, not deprecated versions.
Below are what I understand are the additional packages required on top of a vanilla raspberrypicm4io_64_defconfig to enable graphics support on the CM4:
My config.txt includes the modern KMS overlay:However, kmscube reports the following error:Similarly, /usr/bin/glmark2-es2-drm outputs:Inspecting dmesg, I’ve found lines like this:But I haven’t seen any trace of vc4, which I would expect to appear if the GPU driver were loading correctly.
Running modprobe vc4 results in:This suggests I'm missing something in the Buildroot configuration.
This is where I’m currently stuck. Getting this far has taken several days, and before diving further, I’d like to confirm whether I’m on the right track and making reasonable assumptions.
Any help would be greatly appreciated!
Addendum:
For context: my setup previously worked with earlier kernel versions, starting with 5.15. However, I’ve never fully understood the interplay between different Mesa versions, SDL2/Wayland support, the vc4-kms-v3d-pi4 vs. vc4-fkms-v3d-pi4 overlays, and the Pi 4 firmware.
Right now, my biggest challenge is identifying which documentation and forum posts are still relevant to current versions.
My hardware is based on the CM4, mounted on near-official IO board clones. Two of the setups use LCD displays, and the third uses an HDMI-connected external monitor.
Out of curiosity, I tried switching to: dtoverlay=vc4-fkms-v3d-pi4
But that didn’t help either. I understand this overlay is deprecated now, but it used to be a fallback workaround.
I'm trying to update my two applications to the current 6.12 branch from https://github.com/raspberrypi/linux.
However, even after a clean start, I'm having trouble generating a simple image (using Buildroot 2025.02.3, starting from scratch) that can run kmscube or glmark2 just for testing purposes. I’d appreciate your help in determining the correct selections for kernel configuration, drivers, packages, and config.txt settings for use with CM4 devices at their current, not deprecated versions.
Below are what I understand are the additional packages required on top of a vanilla raspberrypicm4io_64_defconfig to enable graphics support on the CM4:
Code:
# Mesa and its hardware driversBR2_PACKAGE_MESA3D=y # Open-source OpenGL implementationBR2_PACKAGE_MESA3D_OPENGL_ES=y # Embedded Accelerated 3D GraphicsBR2_PACKAGE_MESA3D_OPENGL_EGL=y # EGL window manager interfaceBR2_PACKAGE_MESA3D_GALLIUM_DRIVER_V3D=yBR2_PACKAGE_MESA3D_GALLIUM_DRIVER_VC4=yBR2_PACKAGE_MESA3D_GALLIUM_DRIVER_KMSRO=y# Test utilitiesBR2_PACKAGE_KMSCUBE=yBR2_PACKAGE_GLMARK2=yCode:
dtoverlay=vc4-kms-v3d-pi4Code:
drmGetDevices2 failed: No such file or directorycould not open drm devicefailed to initialize legacy DRMCode:
Error: Can't determine the main graphic card DRM device nodeError: Tried to use '' but failed.Error: Reason: No such file or directoryError: Failed to find a suitable DRM deviceError: main: Could not initialize canvasCode:
[ 242.655838] INFO: task vchiq-keep/0:82 blocked for more than 120 seconds.[ 242.662693] Not tainted 6.12.32-v8 #1Running modprobe vc4 results in:
Code:
Module vc4 not found in directory /lib/modules/6.12.32-v8This is where I’m currently stuck. Getting this far has taken several days, and before diving further, I’d like to confirm whether I’m on the right track and making reasonable assumptions.
Any help would be greatly appreciated!
Addendum:
For context: my setup previously worked with earlier kernel versions, starting with 5.15. However, I’ve never fully understood the interplay between different Mesa versions, SDL2/Wayland support, the vc4-kms-v3d-pi4 vs. vc4-fkms-v3d-pi4 overlays, and the Pi 4 firmware.
Right now, my biggest challenge is identifying which documentation and forum posts are still relevant to current versions.
My hardware is based on the CM4, mounted on near-official IO board clones. Two of the setups use LCD displays, and the third uses an HDMI-connected external monitor.
Out of curiosity, I tried switching to: dtoverlay=vc4-fkms-v3d-pi4
But that didn’t help either. I understand this overlay is deprecated now, but it used to be a fallback workaround.
Statistics: Posted by mrmauro — Fri Jun 06, 2025 6:38 pm — Replies 0 — Views 37