Warning: Device Tree Overlays were introduced in BSP 5. Therefore, this information does not apply to earlier BSPs.
Device Tree Overlays (DTO) provide a way to modify the overall device tree without re-compiling the complete device tree.
Overlays are small pieces, or fragments of a complete device tree, and can be added or removed as needed, often enabling/disabling hardware components in the system.
Because of this flexible nature, overlays provide an advantageous way of describing peripheral hardware that can be added or removed from the system. It is also useful for tweaking the parameters of existing hardware before committing it to a complete device tree.
In a very brief description, the process of designing a Device Tree Overlay comprises three macro steps:
This article will explore these steps for the Toradex BSP Layers and Reference Images for Yocto Project. For information specific to Torizon, see the Device Tree Overlays on Torizon article.
To reduce complexity and also to provide you with example implementations, Toradex provides pre-built Device Tree Overlays for the add-on products (Display and Touch Controllers) available in the webshop. Notice that only for the BSP 5.0 onwards, our reference images offer these Overlays as binaries (.dtbo files).
On a Toradex SoM with the Linux BSP > 5.0 installed, you can list these files available on the boot partition. As an example, using the the terminal of a Apalis iMX8:
$ ls /boot/overlays
display-edt5.7_overlay.dtbo display-lt161010_overlay.dtbo
display-edt7_overlay.dtbo display-lt170410_overlay.dtbo
To enable these overlays, see the Enable/Disable a Device Tree Overlay section. Some overlays are pre-enabled by default, refer to the Pre-enabled Device Tree Overlays section for this.
If you want to obtain the source code of the Device Tree Overlays provided by Toradex for the products available in the webshop, see the Build U-Boot and Linux Kernel from Source Code article.
See the Capacitive Touch Display 7" Parallel in the webshop.
Note: To use capacitive touch interface on Apalis Evaluation board, Colibri Evaluation board and Viola/Viola Plus v1.0-1.2 you need the Capacitive Touch Adapter.
Module | Board | Accessory | Kernel | Overlays |
---|---|---|---|---|
Apalis iMX6 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx6_lcd_overlay.dtbo, apalis-imx6_atmel-mxt_overlay.dtbo | |
Apalis iMX6 | Evaluation/Ixora | toradex_5.4.y | apalis-imx6_parallel-rgb_overlay.dtbo, apalis-imx6_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Apalis iMX8 | Display is not supported by module | |||
Apalis iMX8X | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8x_parallel-rgb_overlay.dtbo, apalis-imx8x_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6_lcd_overlay.dtbo, colibri-imx6_atmel-mxt_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6_parallel-rgb_overlay.dtbo, colibri-imx6_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_atmel-mxt_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_atmel-mxt_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX8X | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx8x_parallel-rgb_overlay.dtbo, colibri-imx8x_atmel-mxt_overlay.dtbo, display-edt7_overlay.dtbo | |
Verdin iMX8MM | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module | |
Verdin iMX8MP | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module |
See the Capacitive Touch Display 10.1" LVDS in the webshop.
Note: To use capacitive touch interface on Apalis Evaluation board, Colibri Evaluation board and Viola/Viola Plus v1.0-1.2 you need the Capacitive Touch Adapter.
Module | Board | Accessory | Kernel | Overlays |
---|---|---|---|---|
Apalis iMX6 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx6_lvds_overlay.dtbo, apalis-imx6_atmel-mxt_overlay.dtbo | |
Apalis iMX6 | Evaluation/Ixora | toradex_5.4.y | apalis-imx6_lvds_overlay.dtbo, apalis-imx6_atmel-mxt_overlay.dtbo, display-lt170410_overlay.dtbo | |
Apalis iMX8 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8_lvds_overlay.dtbo, apalis-imx8_atmel-mxt_overlay.dtbo, display-lt170410_overlay.dtbo | |
Apalis iMX8X | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8x_lvds_overlay.dtbo, apalis-imx8x_atmel-mxt_overlay.dtbo, display-lt170410_overlay.dtbo | |
Colibri iMX6 | Iris v2.0 | toradex_5.4-2.1.x-imx | colibri-imx6_lcd-lvds_overlay.dtbo, colibri-imx6_atmel-mxt_overlay.dtbo | |
Colibri iMX6 | Iris v2.0 | toradex_5.4.y | colibri-imx6_parallel-rgb_overlay.dtbo, colibri-imx6_atmel-mxt_overlay.dtbo, display-dpi-lt170410_overlay.dtbo | |
Colibri iMX6ULL | Iris v2.0 | toradex_5.4-2.1.x-imx | colibri-imx6ull_parallel-rgb-lvds_overlay.dtbo, colibri-imx6ull_atmel-mxt_overlay.dtbo | |
Colibri iMX6ULL | Iris v2.0 | toradex_5.4.y | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_atmel-mxt_overlay.dtbo, display-dpi-lt170410_overlay.dtbo | |
Colibri iMX7 | Iris v2.0 | toradex_5.4-2.1.x-imx | colibri-imx7_parallel-rgb-lvds_overlay.dtbo, colibri-imx7_atmel-mxt_overlay.dtbo | |
Colibri iMX7 | Iris v2.0 | toradex_5.4.y | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_atmel-mxt_overlay.dtbo, display-dpi-lt170410_overlay.dtbo | |
Colibri iMX8X | Iris v2.0 | toradex_5.4-2.1.x-imx | colibri-imx8x_parallel-rgb_overlay.dtbo, colibri-imx8x_atmel-mxt_overlay.dtbo, display-dpi-lt170410_overlay.dtbo | |
Verdin iMX8MM | Development/Dahlia | Verdin DSI to LVDS Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mm_sn65dsi84_overlay.dtbo |
Verdin iMX8MP | Development/Dahlia | Verdin DSI to LVDS Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mp_sn65dsi84_overlay.dtbo |
See the Resistive Touch Display 7" Parallel in the webshop.
Module | Board | Accessory | Kernel | Overlays |
---|---|---|---|---|
Apalis iMX6 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx6_lcd_overlay.dtbo, apalis-imx6_stmpe-ts_overlay.dtbo | |
Apalis iMX6 | Evaluation/Ixora | toradex_5.4.y | apalis-imx6_parallel-rgb_overlay.dtbo, apalis-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | |
Apalis iMX8 | Display is not supported by module | |||
Apalis iMX8X | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8x_parallel-rgb_overlay.dtbo, apalis-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6_lcd_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6_parallel-rgb_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX8X | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx8x_parallel-rgb_overlay.dtbo, colibri-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Verdin iMX8MM | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module | |
Verdin iMX8MP | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module |
See the EDT 7.0" (EOL) in the webshop.
Module | Board | Accessory | Kernel | Overlays |
---|---|---|---|---|
Apalis iMX6 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx6_lcd_overlay.dtbo, apalis-imx6_stmpe-ts_overlay.dtbo | |
Apalis iMX6 | Evaluation/Ixora | toradex_5.4.y | apalis-imx6_parallel-rgb_overlay.dtbo, apalis-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | |
Apalis iMX8 | Display is not supported by module | |||
Apalis iMX8X | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8x_parallel-rgb_overlay.dtbo, apalis-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6_lcd_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6_parallel-rgb_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo | |
Colibri iMX6ULL | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo | |
Colibri iMX7 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Colibri iMX8X | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx8x_parallel-rgb_overlay.dtbo, colibri-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | |
Verdin iMX8MM | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module | |
Verdin iMX8MP | Development/Dahlia | Verdin DSI to RGB Adapter | Display is not (yet) supported by module |
This interface is built into some of Toradex boards. Also, Toradex provides special HDMI adapters:
If the set module+board is not on this list, it doesn't support an HDMI interface.
Module | Board | Accessory | Kernel | Overlays |
---|---|---|---|---|
Apalis iMX6 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx6_hdmi_overlay.dtbo | |
Apalis iMX6 | Evaluation/Ixora | toradex_5.4.y | apalis-imx6_hdmi_overlay.dtbo | |
Apalis iMX8 | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8_hdmi_overlay.dtbo | |
Apalis iMX8X | Evaluation/Ixora | toradex_5.4-2.1.x-imx | apalis-imx8x_dsihdmi_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4-2.1.x-imx | colibri-imx6_hdmi_overlay.dtbo | |
Colibri iMX6 | Evaluation/Aster/Iris/Viola | toradex_5.4.y | colibri-imx6_hdmi_overlay.dtbo | |
Colibri iMX6ULL | Interface is not supported by module | |||
Colibri iMX7 | Interface is not supported by module | |||
Colibri iMX8X | Evaluation/Iris | Colibri iMX8X DSI to HDMI Adapter | toradex_5.4-2.1.x-imx | colibri-imx8x_dsihdmi_overlay.dtbo |
Verdin iMX8MM | Development/Dahlia | Verdin DSI to HDMI Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mm_lt8912_overlay.dtbo |
Verdin iMX8MP | Development/Dahlia | toradex_5.4-2.1.x-imx | verdin-imx8mp_native-hdmi_overlay.dtbo | |
Verdin iMX8MP | Development/Dahlia | Verdin DSI to HDMI Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mp_lt8912_overlay.dtbo |
This interface is built into most of Toradex boards. If the board is not on this list, it doesn't have a VGA interface.
Module | Board | Kernel | Overlays |
---|---|---|---|
Apalis iMX6 | Evaluation | toradex_5.4-2.1.x-imx | apalis-imx6_vga_overlay.dtbo |
Apalis iMX6 | Evaluation | toradex_5.4.y | apalis-imx6_vga_overlay.dtbo |
Apalis iMX8 | Interface is not supported by module | ||
Apalis iMX8X | Interface is not supported by module | ||
Colibri iMX6 | Evaluation/Aster/Iris | toradex_5.4-2.1.x-imx | colibri-imx6_vga_overlay.dtbo |
Colibri iMX6 | Evaluation/Aster/Iris | toradex_5.4.y | colibri-imx6_vga_overlay.dtbo |
Colibri iMX6ULL | Evaluation/Aster/Iris | toradex_5.4-2.1.x-imx | colibri-imx6ull_vga_overlay.dtbo |
Colibri iMX6ULL | Evaluation/Aster/Iris | toradex_5.4.y | colibri-imx6ull_vga_overlay.dtbo |
Colibri iMX7 | Evaluation/Aster/Iris | toradex_5.4-2.1.x-imx | colibri-imx7_vga_overlay.dtbo |
Colibri iMX7 | Evaluation/Aster/Iris | toradex_5.4.y | colibri-imx7_vga_overlay.dtbo |
Colibri iMX8X | Evaluation/Aster/Iris | toradex_5.4-2.1.x-imx | colibri-imx8x_vga_overlay.dtbo |
Verdin iMX8MM | Interface is not supported by module | ||
Verdin iMX8MP | Interface is not supported by module |
Toradex turns on a pre-set of Device Tree Overlays to support the default display interfaces and panels.
Module | Kernel | Overlays | Supported devices |
---|---|---|---|
Apalis iMX6 | toradex_5.4-2.1.x-imx | apalis-imx6_hdmi_overlay.dtbo | HDMI Display |
Apalis iMX6 | toradex_5.4.y | apalis-imx6_hdmi_overlay.dtbo, apalis-imx6_parallel-rgb_overlay.dtbo, apalis-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | HDMI Display, EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Apalis iMX8 | toradex_5.4-2.1.x-imx | apalis-imx8_hdmi_overlay.dtbo | HDMI Display |
Apalis iMX8X | toradex_5.4-2.1.x-imx | apalis-imx8x_hdmi_overlay.dtbo, apalis-imx8x_parallel-rgb_overlay.dtbo, apalis-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | HDMI Display, EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Module | Kernel | Overlays | Supported devices |
---|---|---|---|
Colibri iMX6 | toradex_5.4-2.1.x-imx | colibri-imx6_lcd_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX6 | toradex_5.4.y | colibri-imx6_parallel-rgb_overlay.dtbo, colibri-imx6_stmpe-ts_overlay.dtbo, display-edt7_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX6ULL | toradex_5.4-2.1.x-imx | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX6ULL | toradex_5.4.y | colibri-imx6ull_parallel-rgb_overlay.dtbo, colibri-imx6ull_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX7 | toradex_5.4-2.1.x-imx | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX7 | toradex_5.4.y | colibri-imx7_parallel-rgb_overlay.dtbo, colibri-imx7_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Colibri iMX8X | toradex_5.4-2.1.x-imx | colibri-imx8x_parallel-rgb_overlay.dtbo, colibri-imx8x_ad7879_overlay.dtbo, display-edt7_overlay.dtbo | EDT 7.0" (EOL), Resistive Touch Display 7" Parallel |
Module | Accessory | Kernel | Overlays | Supported devices |
---|---|---|---|---|
Verdin iMX8MM | Verdin DSI to HDMI Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mm_lt8912_overlay.dtbo | HDMI Display |
Verdin iMX8MP | toradex_5.4-2.1.x-imx | verdin-imx8mm_native-hdmi_overlay.dtbo | HDMI Display | |
Verdin iMX8MP | Verdin DSI to HDMI Adapter | toradex_5.4-2.1.x-imx | verdin-imx8mm_lt8912_overlay.dtbo | HDMI Display |
To enable or disable applying a pre-built overlay on a Toradex SoM just add/remove it to/from the file overlays.txt
located on the boot partition, and reboot the system.
For example, one wants to disable a parallel RGB interface and display on Colibri-iMX8X and enable an HDMI interface (using DSI-to-HDMI adapter). The initial overlays.txt
file looks like:
# cat /boot/overlays.txt
fdt_overlays=colibri-imx8x_parallel-rgb_overlay.dtbo colibri-imx8x_ad7879_overlay.dtbo display-edt7_overlay.dtbo
Steps to disable a parallel RGB and enable an HDMI:
overlays.txt
file with any text editor, e.g. vi
:# vi /boot/overlays.txt
# cat /boot/overlays.txt
fdt_overlays=colibri-imx8x_dsihdmi_overlay.dtbo
# sync
# reboot
Note: In case you find yourself with a non-working kernel after applying the overlay, see the Removing a conflicting DTO section.
Note: If you want to obtain the source code of the Device Tree Overlays provided by Toradex for the products available in the webshop, see the Build U-Boot and Linux Kernel from Source Code article.
The most recommended way to create a new overlay is to start looking at our evaluation boards' overlays and then adapt to your project's needs. You can find those overlays in the device-tree-overlays repository.
As with normal device trees, overlays must get explicitly written for the correct kernel version. This depends on the BSP you are using from Toradex and can be checked on Build U-Boot and Linux Kernel from Source Code article.
As an example, here is the device tree overlay for parallel RGB on a Colibri iMX8X (colibri-imx8x_parallel-rgb_overlay.dts):
// Enable the parallel RGB interface on Colibri iMX8X
#include "dt-bindings/gpio/gpio.h"
#include "dt-bindings/pinctrl/pads-imx8qxp.h"
#include "dt-bindings/pwm/pwm.h"
/dts-v1/;
/plugin/;
/ {
compatible = "toradex,colibri-imx8x";
};
&adma_pwm {
status = "okay";
};
&backlight {
brightness-levels = <0 45 63 88 119 158 203 255>;
default-brightness-level = <4>;
power-supply = <®_3v3>;
pwms = <&adma_pwm 0 6666667 PWM_POLARITY_INVERTED>;
status = "okay";
};
&display_lcdif {
status = "okay";
#address-cells = <1>;
#size-cells = <0>;
port@1 {
reg = <1>;
lcd_display_out: endpoint {
remote-endpoint = <&lcd_panel_in>;
};
};
};
&panel_dpi {
status = "okay";
port {
lcd_panel_in: endpoint {
remote-endpoint = <&lcd_display_out>;
};
};
};
This overlay, if loaded, is directly appended to imx8qxp-colibri-eval-v3.dts. This device tree, however, includes the "System on Module Level" device tree imx8qxp-colibri.dtsi which contains most of the device tree nodes.
If the overlay gets loaded, it gets integrated into the already loaded device tree. To add or overwrite properties can be achieved with the ampersand character the same way as described in section Overwriting_properties.
Devicetree overlays have to be denoted with /plugin/;
in the header.
For further reading on this topic, we refer to the kernel documentation: https://www.kernel.org/doc/html/latest/devicetree/overlay-notes.html?highlight=overlays
To build the Device Tree Overlay, see the Build U-Boot and Linux Kernel from Source Code article.
To deploy a custom overlay on a Toradex SoM with the Linux BSP > 5.0 installed:
.dtbo
file to the overlays/
directory in the boot partition;.dtbo
to the overlays.txt
file. This file contains a space separated list of overlays. For example:$ cat /boot/overlays.txt
fdt_overlays=verdin-imx8mm_lt8912_overlay.dtbo verdin-imx8mm_ov5640_overlay.dtbo
After changing the overlays.txt
, run the command sync
and reboot the board. Do not power-cycle because the edits done may not sync to the file system.
Note: In case you find yourself with a non-working kernel after applying the overlay, see the Removing a conflicting DTO section
In case you find yourself with a non-working kernel (normally, stuck at the "Loading kernel..." message), you can delete your custom overlays easily directly from your PC. You would need to set up a USB-OTG connection with your PC and run the UMS functionality of U-Boot by simply stopping the autoboot at U-boot and running the following commands:
ums 0 mmc 0
After this command, you should see a BOOT partition show up on your PC. Delete the conflicting .dtbo and the corresponding item in the overlays.txt file.
Note: Check your carrier board datasheet what ports and jumper configurations work with USB-OTG. In Toradex Carrier Boards, it requires using the correct port or a small jumper removal (like Ixora's JP2).