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Diffstat (limited to 'README.clock')
| -rw-r--r-- | README.clock | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/README.clock b/README.clock new file mode 100644 index 000000000..a8cc98aad --- /dev/null +++ b/README.clock @@ -0,0 +1,39 @@ +Util-linux has always had the clock program (by Charles Hedrick, +Rob Hooft, Harald Koenig, Alan Modra). + +Slackware still uses the clock.c and clock.8 from util-linux-2.6 +(and calls the resulting source fragment clock-1.6.tar.gz). + +Bryan Henderson rewrote it, calling the result hwclock, +and util-linux-2.6 has both clock.c and hwclock.c, +util-linux-2.7 and later only have hwclock.c. + +Unfortunately, hwclock.c was broken in various ways, especially +on non-intel hardware, and distributions started shipping private +versions (usually derived from the old clock). + +For util-linux-2.9k Andries Brouwer took all clock versions around, +and merged them. The resulting hwclock program works on all architectures. +There are some kernel bugs in the handling of /dev/rtc on some i386 hardware, +so under certain circumstances where hwclock fails one has to give it the +--directisa flag to let hwclock do the clock access itself (which works) +rather than leave it to the kernel. [The precise cause is still being +investigated.] +This is the code presently found in the clock subdirectory. + +Bryan Henderson took this code again and merged it with his original +hwclock source. That is the code found in the util-linux-2.9q clock +directory. Unfortunately, this new version didnt work on Sparcs +and in util-linux-2.9r this code was moved to the clockB subdirectory. + + +Executive summary: +clock/hwclock is claimed to be good (but may need the --directisa flag). + + +Comments, bug reports etc are welcome. +Note that the source contains a rather detailed description of the clock +hardware involved. Additions and corrections are welcome. + +Andries +aeb@cwi.nl |