Step 4 : Compile Free-RTOS
==========================

.. tab-set::

   .. tab-item:: Compile Free-RTOS

        * 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>`


.. _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/TImada/raspi4_freertos.git
                
        * Change the current directory to CORTEX_A72_64-bit_Raspberrypi4 as mentioned below. 

        .. code-block:: c

                $ cd raspi4_freertos/FreeRTOS/Demo/CORTEX_A72_64-bit_Raspberrypi4
                

        * Download the following patch and place it in CORTEX_A72_64-bit_Raspberrypi4 directory:

                :download:`add_patch_to_uart.patch <./add_patch_to_uart.patch>`.


        * Apply the changes using the above patch to the uart directory using below command:

        .. code-block:: c

                CORTEX_A72_64-bit_Raspberrypi4$ patch --directory=uart/ --strip=1 < add_patch_to_uart.patch


        * Go to uart directory and build the FreeRTOS UART using below command

        .. code-block:: c

                $ cd uart
                $ make CROSS=aarch64-none-elf-


        * Copy the ``uart.elf`` file to the SD card.

       .. code-block:: c

                $ sudo cp ./uart.elf /mnt/boot/freertos.elf 


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

        What is /.bashrc file?

        .. dropdown:: See Answer

                * ??