Timer : Periodic
=========================


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        :container: container pb-4
        :column: col-lg-12 p-2
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        Topics in this section,

                * :ref:`Version Info <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_1>`

                * :ref:`Learnings in this section <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_2>`

                * :ref:`Complete program : timer.c <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_3>`

                * :ref:`Makefile <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_4>`

                * :ref:`Compile Program <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_5>`

                * :ref:`Load the module <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_6>`

                * :ref:`Check if the module is loaded successfully <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_7>`

                * :ref:`Check what happened on module load <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_8>`

                * :ref:`Unload the module <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_9>`

                * :ref:`Check if the module is unloaded successfully <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_10>`

                * :ref:`Check what happened on module unload <FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_11>`



.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_1:

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

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



.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_2:

.. tab-set::

    .. tab-item:: Learnings in this section

        * In this program, you are going to learn

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                * How to create the kernel timer ?



.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_3:

.. tab-set::

   .. tab-item:: timer.c

        .. literalinclude:: timer_periodic/timer.c
                :language: c
                :linenos:


.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_4:

.. tab-set::

   .. tab-item:: Makefile

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




.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_5:

.. tab-set::

    .. tab-item:: Compile Program
        
        .. code-block:: c
                :linenos:
                :emphasize-lines: 1, 5, 9, 12
                
                $ pwd
                basic_device_drivers/timer_periodic


                $ ls
                timer.c  Makefile 


                $ make


                $ ls
                .depend.timer.o           export_syms             machine                 timer.c               timer_module.ko
                Makefile                  i386                    opt_global.h            timer.o               x86



.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_6:

.. tab-set::

    .. tab-item:: Load the module 

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

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




.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_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   772c70 zfs.ko
		 3    1 0xffffffff828e1000     7850 cryptodev.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     20d4 timer_module.ko


.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_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
		Counter value = 1
		Counter value = 2
		Counter value = 3
		Counter value = 4



.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_9:

.. tab-set::

    .. tab-item:: Unload the module 

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

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




.. _FreebsdDeviceDriver_basic_fdd_timer_timer_periodic_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   772c70 zfs.ko
                 3    1 0xffffffff828e1000     7850 cryptodev.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_timer_timer_periodic_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 loaded
		Counter value = 1
		Counter value = 2
		Counter value = 3
		Counter value = 4
		Counter value = 5
		Counter value = 6
		Module unloaded