.. _ModifyBSP-7:

Modify The BSP
==============

.. include:: ../substitutions.rst
.. include:: ../../common/kirkstone/developingwithyocto/modifyBSP1.rst

Change the Linux Kernel Device Tree
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Let's try making a small change to the kernel's device tree and enable a heartbeat LED using the User LED1 (\ |heartbeat-ref|\ ) to let us know that the system is alive automatically upon boot (this User LED1 is automatically on by default, checkout the GPIO guide to learn more about controlling it as-is):

.. image:: ../../images/phycore-imx7/pcm-061_gpio-D13.webp
   :width: 700px
   :alt: phyCORE-i.MX7 User LED

Use your favorite text editor to open the device tree file corresponding to the |product| development kit's carrier board:

**Host (Ubuntu)**

.. parsed-literal::

    vi |kernel-path|\ arch/arm/boot/dts/imx7s-pba-c-09.dtsi

Edit the file according to the following diff:

**Device Tree Diff**

.. parsed-literal::

    ...
    / {
        pbac09_leds: pbac09-leds {
                compatible = "gpio-leds";
                pinctrl-names = "default";
                pinctrl-0 = <&pinctrl_pbac09_leds>;

                pbac09-led-1 {
                        gpios = <&gpio2 10 GPIO_ACTIVE_HIGH>;
    -                   linux,default-trigger = "gpio";
    +                   linux,default-trigger = "heartbeat";
                        default-state = "on";
                };
        };
    ...

.. include:: ../../common/kirkstone/developingwithyocto/modifyBSP2.rst