:next_page: None
:prev_page: ../packages

.. _linuxbsp:

|Linux| BSP
############

The Embodied Intelligence SDK includes Intel's LTS Kernel v6.12 with Preempt RT patch to support the Arrow Lake platform, which includes the |Linux| Kernel v6.12, optimized configuration, and kernel boot parameters.

Quick Start
************

You can install this component from Intel's Embodied Intelligence SDK repository.

For RT kernel:

.. code-block:: bash

   $ sudo apt install linux-intel-rt-experimental

For generic kernel:

.. code-block:: bash

   $ sudo apt install linux-intel-experimental

Configure and Build |Linux| Kernel
-----------------------------------

The |Linux| BSP Sources are available to download with ``apt-get source`` in addition to support developer to compile by self and deploy on target.
This section will explain the procedure to configure the |Linux| kernel and build it.

**Step 1: Environment Prerequisites**

In this step, you will set up your build environment.

Install additional packages before building a kernel. To do so, run this command:

.. code-block:: bash

   $ sudo apt-get install git fakeroot build-essential ncurses-dev xz-utils libssl-dev bc flex libelf-dev bison debhelper

The command we used above installs the following packages:

.. include:: bsp_depend.rst

**Step 2: Download the Source Code**

   To use below commands to download and extract the kernel source.

For RT kernel:

   .. code-block:: bash

     $ sudo apt-get source linux-intel-rt-experimental
     $ cd linux-intel-rt-experimental*

For generic kernel:

   .. code-block:: bash

     $ sudo apt-get source linux-intel-experimental
     $ cd linux-intel-experimental*

**Step 3: Configure RT Kernel**

   The |Linux| kernel source code comes with the default configuration. Refer to the following list which provides the additional kernel configurations used during compilation to optimize the system for real-time performance.

    +-------------------------------------------------+-----------------------------------------+
    |  kernel config fragment overrides (.cfg)        | Comments                                |
    +=================================================+=========================================+
    |  .. code-block:: console                        |                                         |
    |                                                 |                                         |
    |     CONFIG_HZ_250=y                             | Reduce task scheduling-clock overhead   |
    |     CONFIG_NO_HZ=n                              | and disable CPU governor |Linux| OS     |
    |     CONFIG_NO_HZ_FULL=y                         | features                                |
    |     CONFIG_NO_HZ_IDLE=n                         |                                         |
    |     CONFIG_ACPI_PROCESSOR=n                     |                                         |
    |     CONFIG_CPU_FREQ_GOV_ONDEMAND=n              |                                         |
    |     CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=n      |                                         |
    |     CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y   |                                         |
    |     CONFIG_CPU_FREQ=n                           |                                         |
    |     CONFIG_CPU_IDLE=n                           |                                         |
    |                                                 |                                         |
    +-------------------------------------------------+-----------------------------------------+
    |  .. code-block:: console                        |                                         |
    |                                                 | Disable |Linux| OS power-management     |
    |     ARCH_SUSPEND_POSSIBLE=n                     | runtime features                        |
    |     CONFIG_SUSPEND=n                            |                                         |
    |     CONFIG_PM=n                                 |                                         |
    |                                                 |                                         |
    +-------------------------------------------------+-----------------------------------------+
    |  .. code-block:: console                        |                                         |
    |                                                 |                                         |
    |      CONFIG_VIRT_CPU_ACCOUNTING=y               | Enable more accurate task and           |
    |      CONFIG_VIRT_CPU_ACCOUNTING_GEN=y           | CPU time accounting                     |
    |                                                 |                                         |
    +-------------------------------------------------+-----------------------------------------+
    |  .. code-block:: console                        |                                         |
    |                                                 |                                         |
    |     CONFIG_CPU_ISOLATION=y                      | Enable more preemptive task scheduling  |
    |     CONFIG_RCU_NOCB_CPU=y                       | policies and CPU temporal-isolation     |
    |     CONFIG_PREEMPT_RCU=y                        |                                         |
    |     CONFIG_HAVE_PREEMPT_LAZY=y                  |                                         |
    |     CONFIG_PREEMPT_LAZY=y                       |                                         |
    |     CONFIG_PREEMPT_RT=y                         |                                         |
    |                                                 |                                         |
    +-------------------------------------------------+-----------------------------------------+ 

    You can find a file named ``config-6.12.8-intel-ese-experimental-lts`` in ``/boot/`` when the target had installed with 'sudo apt install linux-intel-rt-experimental', and copy it into |Linux| kernel source directory.

  #. To make changes to the configuration file, run the make command:

     .. code-block:: bash

        $ make olddefconfig

  #. if you need to modify configuration options by menu, run the ``menuconfig`` command:

     .. code-block:: bash

        $ make menuconfig

  Use the arrows to make a selection or choose **Help** to learn more about the options. When you finish making the changes, select **Save**, and then exit the menu.

  **Note:** Changing settings for some options can lead to a non-functional kernel. If you are unsure what to change, leave the default settings.

**Step 4: Build the kernel**

   Starting building the kernel by running the following command:

      .. code-block:: bash

         $ cp build-full/ltsintelrelease .
         $ make ARCH=x86 bindeb-pkg

**Step 5: Install the kernel**
  
   The process of building and compiling the |Linux| kernel takes some time to complete. you will find kernel debian package which can be installed on target with below commands:

      .. code-block:: bash

         $ sudo dpkg -i *.deb
         $ sudo update-grub

   **Note:** When updating or installing packages with `dpkg` on the same kernel, you might encounter issues if the kernel is actively in use. This can happen because certain files or resources are locked or in use by the running kernel, preventing the installation process from completing successfully.

   Here are some strategies to address on this issue:

   1. Switch to Another Kernel.
   2. Force installation with `sudo dpkg -i --force-all *.deb`

**Step 6. Reboot and Verify Kernel version**

   When you complete the steps above, reboot the machine.

   When the system boots up, verify the kernel version using the ``uname`` command:

      .. code-block:: bash

         $ uname -mrs


Packages
*********

* :ref:`Linux-intel-rt-experimental <linuxbsp>`
* customizations-grub