petalinux overlay

### PetaLinux Overlay Usage and Configuration In the context of PetaLinux, overlays are used to modify or extend an existing system without altering its core components. Overlays can be applied at different stages during development and deployment. For configuring overlays within a PetaLinux project: - The `.config` file plays a crucial role in specifying build configurations for U-Boot and Linux kernel settings[^1]. However, this is not directly related to runtime overlays like those found in PYNQ. When integrating with frameworks such as PYNQ that support dynamic overlay loading via Python APIs (like `pynq.Overlay()`), one typically deals with FPGA bitstreams rather than software layers managed by PetaLinux itself[^2]. To work effectively between these two environments: - Ensure environment variables like `XILINX_XRT` point correctly to necessary libraries required for executing hardware-accelerated applications on top of the base OS provided by PetaLinux. - Use tools from both worlds—PetaLinux for building robust embedded systems including drivers and user space utilities; Vitis/PYNQ for rapid prototyping involving custom IP cores and high-level synthesis flows targeting FPGAs. While direct documentation about "overlays" specifically under PetaLinux might focus more on package management aspects instead of run-time reconfiguration capabilities similar to what's offered through PYNQ’s API calls, understanding how each toolchain contributes towards final application design remains essential. ```bash # Example command setting up XRT path which may indirectly affect overlay operations when interfacing with PYNQ export XILINX_XRT=/usr ``` --related questions-- 1. How does one configure environment variables properly before running applications requiring XRT? 2. What steps should users follow to integrate Vitis-generated executables into a PYNQ-based workflow? 3. Can you provide guidance on modifying the default .config files generated by PetaLinux projects? 4. In what ways do PetaLinux and PYNQ complement each other regarding hardware acceleration tasks?