The device tree is a data structure that describes the hardware components available on a system. The Linux kernel queries the device tree to know what drivers to load during boot.

Device tree file types

Device tree files are located at arch/arm/boot/dts/ and can have two extensions:

  • .dtsi files are device tree source include files. They describe hardware that is common to several platforms which include these files on their .dts files.

  • .dts files are device tree source files. They describe one specific platform.

ConnectCore 6 system-on-module

The ConnectCore 6 is a system-on-module (SOM) solution that integrates:

  • NXP i.MX6 system-on-chip featuring many interfaces such as UART, CAN, SPI, and I2C

  • DDR3 memory

  • eMMC memory

  • PMIC chip

  • Optional Wi-Fi chip

  • Optional Bluetooth chip

  • Optional Kinetis chip

The ConnectCore 6 system-on-module needs to be soldered to a carrier board. For this reason, there is not a single .dts file for it. Instead, its hardware features are collected into .dtsi files that can be included by a final platform .dts. Since the ConnectCore 6 system-on-module is offered in different variants, multiple .dtsi files have been defined to describe the hardware inside:

File Description


Common hardware for ConnectCore 6 system-on-chip (SOC) variants with either Quad/Dual CPU or Solo/DualLite CPU


ConnectCore 6 system-on-module variant with Quad/Dual CPU and Wi-Fi (no Bluetooth)


ConnectCore 6 system-on-module variant with Quad/Dual CPU, Wi-Fi, and Bluetooth


ConnectCore 6 system-on-module variant with Solo/DualLite CPU and Wi-Fi (no Bluetooth)


ConnectCore 6 system-on-module variant with Solo/DualLite CPU, Wi-Fi, and Bluetooth

ConnectCore 6 SBC

The ConnectCore 6 SBC is a carrier board assembling the ConnectCore 6 system-on-module. The carrier board assembles additional hardware like a video port, Ethernet PHY, audio chip, PCIe minicard, microSD card holder, user LEDs, and so on.

As a final platform, the carrier board has a .dts file that includes one of the ConnectCore 6 system-on-module .dtsi files.

Include files

The SBC can assemble different variants of the ConnectCore 6 system-on-module, so the common hardware of the SBC is also described in several .dtsi files:

File Description


Common hardware for ConnectCore 6 SBC assembling a Quad/Dual or Solo/DualLite ConnectCore 6 system-on-module


Common hardware for ConnectCore 6 SBC assembling a Quad/Dual ConnectCore 6 system-on-module


Common hardware for ConnectCore 6 SBC assembling a Solo/DualLite ConnectCore 6 system-on-module

The last two files include the common file imx6qdl-ccimx6sbc.dtsi.

Final platform files

The final platforms are described in board-specific .dts files:

File Digi product smart part number CPU family Wi-Fi Bluetooth










Graphical representation

The following graphic illustrates the composition of a .dts file.

ConnectCore 6 device tree files

Device tree selection during boot process

Digi Embedded Yocto builds the different device tree files (.dts) for different boards and SOM variants into binary device tree blobs (.dtb). The device tree blobs are placed inside the linux partition along with the kernel binary.

The bootloader uses the board_id variable to determine which device tree blob to use when booting the system. See Carrier board version and ID.

To learn how to create a device tree for your custom carrier board and using a custom board ID, see Add a new custom machine.