# Overlay functionality and driver module blacklisting overview

The `qcom-multimedia-proprietary-image` image recipe in the `meta-qcom-distro` OpenEmbedded layer includes
the recipes for all the overlays, which results in the components that are built into the image.

The following artifacts are generated:

- Kernel driver modules
- Libraries
- Binaries

When the image is flashed, it’s set up such that the overlays can be used for various functionalities. The recipes for driver modules use module blacklisting to blacklist the upstream module
from being loaded at boot, which leads to the Qualcomm Linux overlay kernel driver module to load.

Overlay for camera requires an additional configuration, that is, writing to an EFI variable from the Linux shell for the
CamX driver module to be loaded at bootup. After this EFI variable is set on first boot, the overlay runs as default on all subsequent boots. In other words, the CamX kernel module driver is loaded at bootup.

The following table lists where module blacklisting and EFI variables are used for overlays:

Table: Overlays, corresponding module blacklisting, and EFI variable

| Technology | Uses module blacklisting | Uses EFI variable |
| --- | --- | --- |
| Audio | Yes | No |
| Camera | No | Yes |
| Graphics | Yes | No |
| Video | Yes | No |
| Sensors | No | No |
| Vision | No | No |

Note

For QCS615-based devices, such as the IQ-615 EVK, the video overlay functionality isn’t supported. If you have flashed an image, such as `qcom-multimedia-proprietary-image`, [enable the upstream video driver](https://docs.qualcomm.com/doc/80-80022-254/topic/enable_dtb_overlay.html#enable-dtb-overlay). If you are using one of the overlay workflows to install packages, you don’t need to install video packages for the QCS615 hardware.

Last Published: May 12, 2026

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