.. _ModifyBSP-64:

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

.. include:: ../substitutions.rst
.. include:: ../../common/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-am64x/pb-07225_gpio_led1-d30.png
   :width: 700px
   :alt: LED1 (D30)

Use your favorite text editor to open the main device tree file for the |product| development kit:

**Host (Ubuntu)**

.. parsed-literal::

    vi |kernel-path|/|kernel-dts-path|

Edit the file according to the following diff:

**Device Tree Diff**

.. parsed-literal::

    ...
                leds {
                    compatible = "gpio-leds";
                    pinctrl-names = "default";
                    pinctrl-0 = <&leds_pins_default>, <&user_leds_pins_default>;

                    led-1 {
    -                       color = <LED_COLOR_ID_RED>;
                            gpios = <&main_gpio0 15 GPIO_ACTIVE_HIGH>;
    -                       linux,default-trigger = "mmc0";
    -                       function = LED_FUNCTION_DISK;
    +                       linux,default-trigger = "heartbeat";
                    };

                    led-2 {
    ...

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