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Working with kernel

Device Tree Overlays​

Device Tree Overlays provide a way to modify or extend the base Device Tree without changing the original Device Tree Source (DTS) file. Overlays are particularly useful in scenarios where you need to enable or configure additional hardware components dynamically or after the system has already booted.

Why Use Device Tree Overlays?​

  • Flexibility: Overlays allow you to make changes to the hardware configuration without modifying the core Device Tree. This is especially useful for systems with add-on modules, expansion boards, or configurable peripherals.
  • Modularity: Overlays can be loaded and unloaded as needed, making them ideal for systems where hardware can change dynamically, such as during prototyping or in modular systems like HATs.

Structure of a Device Tree Overlay​

A Device Tree Overlay (.dtbo file) is a binary file similar to a Device Tree Blob (DTB). The overlay file is generated from a Device Tree Source Overlay (DTSO) file. The DTSO describes the modifications to be applied to the base Device Tree.