Skip to content

Latest commit

 

History

History
64 lines (49 loc) · 2.09 KB

running_linux.md

File metadata and controls

64 lines (49 loc) · 2.09 KB
Raw

Running using a layer on Linux

There are multiple ways to install layer drivers for Linux. For our use case we cannot usually modify the application binary, so we install the layer and manifest into a user-owned directory on the target device and configure the layer driver using environment options.

Create a manifest

Layers are specified to the system loader using a JSON manifest file. This file must be called manifest.json and saved into a directory on the target device. The example below shows the manifest for a generated layer called "Fizzbuzz".

{
  "file_format_version": "1.1.2",
  "layer": {
      "name": "VK_LAYER_LGL_FIZZBUZZ",
      "type": "INSTANCE",
      "library_path": "./libVkLayerFizzbuzz.so",
      "api_version": "1.2.162",
      "implementation_version": "1",
      "description": "Vulkan layer that does something useful and interesting."
  }
}

Install the layer

Copy the built layer into the same directory as the manifest on the target device.

Run the application

Our layer is not a system layer, so we use environment variables to tell the Vulkan loader that our layer exists and where to load it from.

Assuming both the manifest (manifest.json) and the built layer binary (libVkLayerFizzbuzz.so) are saved in the vkwork directory in the user home area, the following command should run the Vulkan vkcube sample with the Fizzbuzz layer loaded.

env VK_LOADER_DEBUG=all \
    VK_LAYER_PATH=$VK_LAYER_PATH:/home/${USER}/vkwork \
    LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/${USER}/vkwork \
    VK_INSTANCE_LAYERS=VK_LAYER_LGL_FIZZBUZZ \
    vkcube

The VK_LOADER_DEBUG=all option enables verbose logging in the loader itself, and is a useful tool that can help you work out why your layer is not being loaded when you expect. Once your layer is being loaded correctly, this option can be removed.

Uninstall

If you follow the steps above, no persistent system state is modified. Running an application without any of the environment variables set will run without the Fizzbuzz layer installed.

Copyright © 2024, Arm Limited and contributors.