# Configure alternative drivers

## Enable camera overlays

Note

This section applies only to QCS6490, IQ-9075, and IQ-8275.

When you flash and boot `qcom-multimedia-proprietary-image`, the upstream camera stack is enabled by default. You can change this setting by updating the EFI variable.

Update the EFI variable at runtime after the device boots. On the first boot, set the EFI variable using the sysfs node, then reboot to enable CAMX on subsequent boots.

Apply the DTB Overlay:

# The -n option is mandatory for EFI variables
    # Expect the exact data without trailing newline characters.
    echo -n "camx" > /tmp/overlay
    
    # The EFI variable used to control the overlays loaded during UEFI
    # boot is 882f8c2b-9646-435f-8de5-f208ff80c1bd-VendorDtbOverlays.
    # Use efivar to write the data into the runtime EFI variable
    efivar -n 882f8c2b-9646-435f-8de5-f208ff80c1bd-VendorDtbOverlays -w -f /tmp/overlay
    
    # Print the EFI variable for confirmation
    efivar -n 882f8c2b-9646-435f-8de5-f208ff80c1bd-VendorDtbOverlays -p
    
    # Reboot to reflect the changes
    sync
    reboot
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After rebooting, you can check the UEFI serial logs to verify that the camx overlay has
been applied. Below is an example log snippet captured from the iq‑8275‑evk platform:

Variable VendorDtbOverlays read successfully. Data: camx
    ProcessQcomRuntimeOverlayRequest: Parsed camx
    
    FindConfigToBoot:Booting with = qcom,qcs8275-iot-camx
    FindConfigToBoot: i = 0 fdt fdt-monaco-evk.dtb str len = 18
    FindConfigToBoot: i = 1 fdt fdt-monaco-evk-camx.dtbo str len = 24
    ParseFitDt::
    Config fdt-monaco-evk.dtb & Type 0
    Config fdt-monaco-evk-camx.dtbo & Type 1
    FitLoadDtbFromFdt: Config fdt-monaco-evk.dtb & Type 0
    FitLoadDtbFromFdt: Config fdt-monaco-evk-camx.dtbo & Type 1
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## Enable upstream video driver

Note

This section applies only to the IQ‑615 EVK.

IQ‑615 EVK supports only the upstream video driver `venus`. The video overlay functionality is not supported.

When you flash and boot `qcom-multimedia-proprietary-image`, the upstream video driver is not enabled by default. This can be changed by updating the kernel module configuration.

Enable the upstream video driver:

update-alternatives --install /etc/modprobe.d/blacklist-video.conf blacklist-video /etc/modprobe.d/blacklist-video.conf.vidc 200
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After rebooting the device, you can run `lsmod` to confirm if the changes have been applied.

lsmod | grep venus
    # Expected Output
    # venus_enc           28672   0
    # venus_dec           28672   0
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Last Published: May 22, 2026