Device Tree (also known as Device Tree Blob, DTB) in Linux is significantly improves the portability, maintainability, and configurability of the Linux kernel in embedded systems, by a standardized and flexible mechanism for describing hardware configurations, allowing the same kernel image to run on various hardware platforms and enabling easier development and maintenance of embedded systems. It basically encourages code reuse, and allows developers to focus on the application logic rather than dealing with low-level hardware details.
Below are key points of device tree in Linux,
1. Kernel-Device Separation: Device Tree separates hardware configuration details from the kernel source code. This separation makes it easier to maintain and modify the device configuration without changing the kernel source. Additionally, it simplifies the process of adding support for new hardware without modifying the kernel itself.
2. Hardware Abstraction: Due to Kernel-Device Separation, it solves the traditional approach of directly compiling hardware details into the kernel which was challenging to support various hardware platforms.
3. Dynamic Hardware Configuration: In embedded systems, hardware configurations can vary depending on the specific hardware platform or system-on-chip (SoC). Device Tree allows for dynamic configuration at runtime, meaning the same kernel image can be used on multiple hardware platforms without recompiling the kernel for each specific platform.
4. Simplified Device Driver Development: Device Tree enables device drivers to be written in a more generic and platform-independent manner. Drivers can rely on the information provided by the Device Tree to understand the hardware layout and register mappings, resulting in easier development and better driver portability.
5. Flexibility for Custom Hardware: Many embedded systems involve custom hardware designs with unique peripherals. Device Tree allows developers to describe these custom hardware components in a standardized way, ensuring that the kernel can correctly configure and interact with these custom devices.
6.Reduced Kernel Image Size: Since hardware configuration details are stored separately in the Device Tree Blob, the kernel image size is reduced, which is crucial for resource-constrained embedded systems.
7.Ease of Configuration for Bootloaders: Device Tree is also used by bootloaders to pass hardware configuration information to the kernel. This simplifies the bootloader's role in setting up the hardware correctly before handing control over to the kernel.