40 lines
1.6 KiB
Plaintext
40 lines
1.6 KiB
Plaintext
Util-linux has always had the clock program (by Charles Hedrick,
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Rob Hooft, Harald Koenig, Alan Modra).
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Slackware still uses the clock.c and clock.8 from util-linux-2.6
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(and calls the resulting source fragment clock-1.6.tar.gz).
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Bryan Henderson rewrote it, calling the result hwclock,
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and util-linux-2.6 has both clock.c and hwclock.c,
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util-linux-2.7 and later only have hwclock.c.
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Unfortunately, hwclock.c was broken in various ways, especially
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on non-intel hardware, and distributions started shipping private
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versions (usually derived from the old clock).
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For util-linux-2.9k Andries Brouwer took all clock versions around,
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and merged them. The resulting hwclock program works on all architectures.
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There are some kernel bugs in the handling of /dev/rtc on some i386 hardware,
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so under certain circumstances where hwclock fails one has to give it the
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--directisa flag to let hwclock do the clock access itself (which works)
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rather than leave it to the kernel. [The precise cause is still being
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investigated.]
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This is the code presently found in the clock subdirectory.
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Bryan Henderson took this code again and merged it with his original
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hwclock source. That is the code found in the util-linux-2.9q clock
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directory. Unfortunately, this new version didnt work on Sparcs
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and in util-linux-2.9r this code was moved to the clockB subdirectory.
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Executive summary:
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clock/hwclock is claimed to be good (but may need the --directisa flag).
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Comments, bug reports etc are welcome.
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Note that the source contains a rather detailed description of the clock
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hardware involved. Additions and corrections are welcome.
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Andries
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aeb@cwi.nl
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