Kthread
==============


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

        Topics in this section,

                * :ref:`Version Info <FreebsdDeviceDriver_basic_fdd_kthread_1>`

                * :ref:`Learnings in this section <FreebsdDeviceDriver_basic_fdd_kthread_2>`

                * :ref:`Complete program : kthread.c <FreebsdDeviceDriver_basic_fdd_kthread_3>`

                * :ref:`Makefile  <FreebsdDeviceDriver_basic_fdd_kthread_4>`

                * :ref:`Compile Program <FreebsdDeviceDriver_basic_fdd_kthread_5>`

                * :ref:`Load the module <FreebsdDeviceDriver_basic_fdd_kthread_6>`

                * :ref:`Check if the module is loaded successfully <FreebsdDeviceDriver_basic_fdd_kthread_7>`

                * :ref:`Check what happened on module load <FreebsdDeviceDriver_basic_fdd_kthread_8>`

                * :ref:`Unload the module <FreebsdDeviceDriver_basic_fdd_kthread_9>`

                * :ref:`Check if the module is unloaded successfully <FreebsdDeviceDriver_basic_fdd_kthread_10>`

                * :ref:`Check what happened on module unload <FreebsdDeviceDriver_basic_fdd_kthread_11>`



.. _FreebsdDeviceDriver_basic_fdd_kthread_1:

.. tab-set::
 
    .. tab-item:: Version Info

        =============================== =======================================
        #                               Version
        =============================== =======================================
        Freebsd                         14.1.0
        =============================== =======================================



.. _FreebsdDeviceDriver_basic_fdd_kthread_2:

.. tab-set::

    .. tab-item:: Learnings in this section

        * In this program, you are going to learn

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

                * How to create the kernel thread ?

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

                * How to stop the kernel thread ?



.. _FreebsdDeviceDriver_basic_fdd_kthread_3:

.. tab-set::

   .. tab-item:: kthread.c

        .. literalinclude:: kthread/kthread.c
                :language: c
                :linenos:



.. _FreebsdDeviceDriver_basic_fdd_kthread_4:

.. tab-set::

   .. tab-item:: Makefile

        .. literalinclude:: kthread/Makefile
                :language: c
                :linenos:


.. _FreebsdDeviceDriver_basic_fdd_kthread_5:

.. tab-set::

    .. tab-item:: Compile Program

	* Run make command to compile 
        
        .. code-block:: c
                :linenos:
                :emphasize-lines: 1, 5, 9, 12
                

                $ pwd
                basic_device_drivers/kthread


                $ ls
                kthread.c  Makefile 


                $ make


		$ ls
		.depend.kthread.o       export_syms             kthread.c               kthread_module.ko       opt_global.h
		Makefile                i386                    kthread.o               machine                 x86


.. _FreebsdDeviceDriver_basic_fdd_kthread_6:

.. tab-set::

    .. tab-item:: Load the module 

        * Load the module using kldload
        
        .. code-block:: c
		:linenos:
                :emphasize-lines: 1

                $ kldload -v ./kthread_module.ko
		Loaded ./kthread_module.ko, id=8



.. _FreebsdDeviceDriver_basic_fdd_kthread_7:

.. tab-set::

    .. tab-item:: Check if the module is loaded successfully

	* Run kldstat command to check the loaded modules

        .. code-block:: c
		:linenos:
                :emphasize-lines: 1, 10

                $ kldstat
		Id Refs Address                Size Name
		 1   29 0xffffffff80200000  1f6c698 kernel
		 2    1 0xffffffff8216d000     7850 cryptodev.ko
		 3    1 0xffffffff82176000   772c70 zfs.ko
		 4    1 0xffffffff83218000     3220 intpm.ko
		 5    1 0xffffffff8321c000     2178 smbus.ko
		 6    1 0xffffffff8321f000     3360 uhid.ko
		 7    1 0xffffffff83223000     3360 wmt.ko
		 8    1 0xffffffff83227000     209c kthread_module.ko


.. _FreebsdDeviceDriver_basic_fdd_kthread_8:

.. tab-set::

    .. tab-item:: Check what happened on module load

	* Run dmesg command to check the kernel logs

        .. code-block:: c
                :linenos:
                :emphasize-lines: 1

		$ dmesg
		Module loaded
		Kthread is running
		Kthread is running
		Kthread is running
		Kthread is running
		Kthread is running


.. _FreebsdDeviceDriver_basic_fdd_kthread_9:

.. tab-set::

    .. tab-item:: Unload the module 

        * Unload the module using kldunload
        
        .. code-block:: c
                :linenos:
                :emphasize-lines: 1

                $ kldunload -v ./kthread_module.ko
		Unloading kthread_module.ko, id=8


.. _FreebsdDeviceDriver_basic_fdd_kthread_10:

.. tab-set::

    .. tab-item:: Check if the module is unloaded successfully

	* Run kldstat command to check the loaded modules

        .. code-block:: c
                :linenos:
                :emphasize-lines: 1

                $ kldstat
		Id Refs Address                Size Name
		 1   27 0xffffffff80200000  1f6c698 kernel
		 2    1 0xffffffff8216d000     7850 cryptodev.ko
		 3    1 0xffffffff82176000   772c70 zfs.ko
		 4    1 0xffffffff83218000     3220 intpm.ko
		 5    1 0xffffffff8321c000     2178 smbus.ko
		 6    1 0xffffffff8321f000     3360 uhid.ko
		 7    1 0xffffffff83223000     3360 wmt.ko


.. _FreebsdDeviceDriver_basic_fdd_kthread_11:

.. tab-set::

    .. tab-item:: Check what happened on module unload

	* Run dmesg command to check the kernel logs

        .. code-block:: c
                :linenos:
                :emphasize-lines: 1

                $ dmesg
		Module unloaded