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git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@771 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
108 lines
2.7 KiB
XML
108 lines
2.7 KiB
XML
<sect1 id="ch07-setclock">
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<title>Creating the setclock script</title>
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<para>
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The following script is only for real use when the hardware clock (also
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known as BIOS or CMOS clock) isn't set to GMT time. The recommended
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setup is setting the hardware clock to GMT and having the time converted
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to localtime using the /etc/localtime symbolic link. But if an
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OS is run that doesn't understand a clock set to GMT (most notable are
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Microsoft OS'es) a user might want to set the clock to localtime so that
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the time is properly displayed on those OS'es. This script will reset
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the kernel time to the hardware clock without converting the time using
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the /etc/localtime symlink.
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</para>
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<para>
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If you want to use this script on your system even if the
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hardware clock is set to GMT, then the UTC variable below has to be changed
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to the
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value of <emphasis>1</emphasis>.
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</para>
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<para>
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<screen>
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<userinput>cat > setclock << "EOF"</userinput>
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#!/bin/sh
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# Begin /etc/init.d/setclock
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#
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# Include the functions declared in the /etc/init.d/functions file
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# and include the variables from the /etc/sysconfig/clock file
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#
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source /etc/init.d/functions
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source /etc/sysconfig/clock
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#
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# Right now we want to set the kernel clock according to the hardware
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# clock, so we use the -hctosys parameter.
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#
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CLOCKPARAMS="--hctosys"
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#
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# If the UTC variable is set in the /etc/sysconfig/clock file, add the
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# -u parameter as well which tells hwclock that the hardware clock is
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# set to UTC time instead of local time.
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#
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case "$UTC" in
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yes|true|1)
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CLOCKPARAMS="$CLOCKPARAMS --utc"
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;;
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no|false|0)
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CLOCKPARAMS="$CLOCKPARAMS --localtime"
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;;
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esac
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echo -n "Setting clock..."
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/sbin/hwclock $CLOCKPARAMS
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evaluate_retval
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# End /etc/init.d/setclock
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<userinput>EOF</userinput>
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</screen>
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</para>
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<sect2>
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<title>Creating the /etc/sysconfig/clock file</title>
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<para>
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Create a new file <filename>/etc/sysconfig/clock</filename> by running
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the following:
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</para>
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<para>
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<screen>
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<userinput>cat > /etc/sysconfig/clock << "EOF"</userinput>
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# Begin /etc/sysconfig/clock
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UTC=1
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# End /etc/sysconfig/clock
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<userinput>EOF</userinput>
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</screen>
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</para>
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<para>
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If the hardware clock (also known as BIOS or CMOS clock) is not set to
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GMT time, then the UTC variable in the /etc/sysconfig/clock file needs to be
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set to
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the value <emphasis>0</emphasis> (zero).
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</para>
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<para>
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Now, you may want to take a look at a very good hint explaining how we
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deal with time on LFS at
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<ulink url="http://archive.linuxfromscratch.org/lfs-hints/time.txt">
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http://archive.linuxfromscratch.org/lfs-hints/time.txt</ulink>.
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It explains issues such as timezones, UTC, and the TZ
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environment variable.
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</para>
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</sect2>
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</sect1>
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