45 lines
1.4 KiB
ReStructuredText
45 lines
1.4 KiB
ReStructuredText
.. zephyr:code-sample:: posix-gettimeofday
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:name: gettimeofday() with clock initialization
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Use ``gettimeofday()`` with clock initialization over SNTP.
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Overview
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********
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This sample application demonstrates using the POSIX `gettimeofday()`_ function to display the
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absolute wall clock time and local time every second. At system startup, the current time is
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queried using the SNTP networking protocol, enabled by setting the
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:kconfig:option:`CONFIG_NET_CONFIG_CLOCK_SNTP_INIT` and
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:kconfig:option:`CONFIG_NET_CONFIG_SNTP_INIT_SERVER` options.
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Requirements
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************
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- :ref:`networking_with_host`
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- or, a board with hardware networking
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- NAT/routing should be set up to allow connections to the Internet
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- DNS server should be available on the host to resolve domain names
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Building and Running
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********************
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This project outputs to the console. It can be built and executed on QEMU as follows:
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.. zephyr-app-commands::
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:zephyr-app: samples/posix/gettimeofday
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:host-os: unix
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:board: qemu_x86
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:goals: run
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:compact:
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For comparison, to build directly for your host OS if it is POSIX compliant (for ex. Linux):
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.. code-block:: console
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cd samples/posix/gettimeofday
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make -f Makefile.host
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The make output file will be located in samples/posix/gettimeofday/build.
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.. _gettimeofday(): https://pubs.opengroup.org/onlinepubs/009604599/functions/gettimeofday.html
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