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Piotr Zięcik ec857d0e4a logging: Do not use CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC On some SoCs the frequency of the system clock is obtained at run time as the exact configuration of the hardware is not known at compile time. On such platforms using CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC define directly introduces timing errors. This commit replaces CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC by the call to inline function sys_clock_hw_cycles_per_sec() which always returns correct frequency of the system clock. Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>		2019-07-24 15:10:02 +02:00
..
src
CMakeLists.txt
Kconfig
prj_rtt.conf
prj.conf
README.rst
sample.yaml

README.rst

.. _logger_sample:

Logging
###########

Overview
********
A simple application that demonstrates use of logging subsystem. It demonstrates
main features: severity levels, timestamping, module level filtering and
instance level filtering. It also showcases logging capabilities in terms of
performance.

Building and Running
********************

This project outputs multiple log message to the console.  It can be built and
executed on QEMU as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/subsys/logging/logger
   :host-os: unix
   :board: qemu_x86
   :goals: run
   :compact:


Sample Output
=============

.. code-block:: console

        Module logging showcase.
        [00:00:00.106,051] <inf> sample_module: log in test_module 11
        [00:00:00.106,054] <inf> sample_module: Inline function.
        Disabling logging in the sample_module module
        Function called again but with logging disabled.
        Instance level logging showcase.
        [00:00:00.106,200] <inf> sample_instance.inst1: Inline call.
        [00:00:00.106,204] <inf> sample_instance.inst1: counter_value: 0
        [00:00:00.106,209] <wrn> sample_instance.inst1: Example of hexdump:
        01 02 03 04             |....
        [00:00:00.106,214] <inf> sample_instance.inst2: Inline call.
        [00:00:00.106,218] <inf> sample_instance.inst2: counter_value: 0
        [00:00:00.106,223] <wrn> sample_instance.inst2: Example of hexdump:
        01 02 03 04             |....
        Changing filter to warning on sample_instance.inst1 instance.
        [00:00:00.106,297] <wrn> sample_instance.inst1: Example of hexdump:
        01 02 03 04             |....
        [00:00:00.106,302] <inf> sample_instance.inst2: Inline call.
        [00:00:00.106,307] <inf> sample_instance.inst2: counter_value: 1
        [00:00:00.106,311] <wrn> sample_instance.inst2: Example of hexdump:
        01 02 03 04             |....
        Disabling logging on both instances.
        Function call on both instances with logging disabled.
        String logging showcase.
        [00:00:01.122,316] <inf> main: Logging transient string:transient_string
        Severity levels showcase.
        [00:00:01.122,348] <err> main: Error message example.
        [00:00:01.122,352] <wrn> main: Warning message example.
        [00:00:01.122,355] <inf> main: Info message example.
        Logging performance showcase.
        [00:00:02.151,602] <inf> main: performance test - log message 0
        Estimated logging capabilities: 42000000 messages/second
        Logs from external logging system showcase.
        [00:00:03.165,977] <err> ext_log_system: critical level log
        [00:00:03.165,991] <err> ext_log_system: error level log, 1 arguments: 1
        [00:00:03.166,006] <wrn> ext_log_system: warning level log, 2 arguments: 12
        [00:00:03.166,025] <inf> ext_log_system: notice level log, 3 arguments: 105
        [00:00:03.166,044] <inf> ext_log_system: info level log, 4 arguments : 1 24