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    SubjectRe: updating the RTC automagically
    On Fri, Nov 19, 1999 at 08:10:25AM +0200, Ulrich Windl wrote:

    > > (ii) This would add a very large amount of bloat without any
    > > increase in functionality.
    > I think it would be a great chance to fix hardware dependent things
    > where it is the best place. What can hwclock do that the kernel
    > can't, or: How can hwclock set the kernel, if the kernel can't. Would
    > you implement code for any of the platforms using #ifdef or what?

    You can read the code, say in util-linux-2.10*.

    This time-setting stuff is a bit of a mess - not all chips follow
    the original mc146818rtc in all details.
    The result is that, even though kernel (/dev/rtc) and "hwclock --directisa"
    do more or less the same things, "hwclock --directisa" succeeds in some
    cases, where the kernel fails (e.g., hangs). I think I do not know of cases
    where the two possible approaches of hwclock, namely via /dev/rtc and via
    direct port access, both fail.

    > I don't want to put the DST decision logic into the kernel,
    > just the timezone offset.
    > The latter is needed by DOSish filesystems anyway.

    But the timezone offset is already maintained in the kernel.
    (The way it is done is broken, but that is a different matter.)
    And hwclock tells the kernel about the present timezone.


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