Step 3 : u-boot compilation
===========================

.. tab-set::

   .. tab-item:: u-boot compilation

        * In this program, you are going to learn


        .. panels::
                :container: container pb-4
                :column: col-lg-12 p-2
                :card: shadow

                * How to ?


.. panels::
        :container: container pb-4
        :column: col-lg-12 p-2
        :card: shadow

        Topics in this section,

                * :ref:`Source code download and compilation <freertos_rpi_4b_step4_0>`

                * :ref:`Copy the binary to your SD card <freertos_rpi_4b_step4_1>`


.. _freertos_rpi_4b_step4_0:

.. tab-set::

   .. tab-item:: Source code download and compilation

        * Make sure current dir is $HOME
        
        .. code-block:: c

                $ cd $HOME

        * Use below command to doenload the source code.

        .. code-block:: c

                $ git clone https://github.com/u-boot/u-boot

        * Compilation

        .. code-block:: text

                $ cd u-boot
                $ export CROSS_COMPILE=aarch64-none-elf-
                $ echo 'CONFIG_CMD_CACHE=y' >> ./configs/rpi_4_defconfig
                $ make rpi_4_defconfig
                $ make -j4 (if your PC has 4 processor cores)


.. _freertos_rpi_4b_step4_1:

.. tab-set::

   .. tab-item:: Copy the u-boot binary to your SD Card

        .. code-block:: c

                $ sudo cp ./u-boot.bin /mnt/boot/u-boot.bin


.. panels::
        :container: container pb-4
        :column: col-lg-12 p-2
        :card: shadow

        What is ?

        .. dropdown:: See Answer

                * ??