2 Device Tree Source Inclusion

Device trees can be split into several files. For example, the device tree for the SAM9X60 device and the SAM9X60-Curiosity board is split into .dts (“device tree source”) and .dtsi (“device tree source include”) files.

.dts files are board-level definitions. .dtsi files generally contain SoC-level definitions and are included in .dts files. Device tree files are not monolithic; they can be split into several files, including each other.

By convention, .dtsi files include definitions of SoC-level information, while .dts files are final device trees containing board-level information. The inclusion works by overlaying the tree of the including file over the tree of the included file, producing a combined compiled binary blob, as shown below.

Figure 2-1. Device Tree Blob (DTB) Generation

Note: The actual DTB is in binary format. The above example shows an equivalent of DTB contents.