Subject: Re: RTC DST bit?
To: Rick Byers <firstname.lastname@example.org>
From: Andrew Brown <email@example.com>
Date: 04/14/2000 15:23:48
>I (unfortunantly) must run Windows on my main PC, in addition to
>NetBSD. This makes the real-time clock stuff a bit of a pain (see
>RTC_OFFSET in options(4)). I usually just change RTC_OFFSET by hand twice
>a year. However, I was thinking maybe it wouldn't be too difficult to
>eliminate this (without giving NetBSD a bogus timezone that doesn't use
freebsd has a "solution" as well, which it probably closer to the bsd
framework that anything from linux.
% grep kern /etc/crontab
# See adjkerntz(8) for details.
1,31 0-4 * * * root /sbin/adjkerntz -a
% ls -l /etc/wall_cmos_clock
-rw-r--r-- 1 root wheel 0 Jul 22 1997 /etc/wall_cmos_clock
% man adjkerntz
Adjkerntz maintains the proper relationship between the kernel clock,
which is always set to UTC, and the CMOS clock, which may be set to local
time. Adjkerntz also informs the kernel about machine timezone shifts to
maintain proper timestamps for local time file systems such as the MS-DOS
file system. The main purpose of this thing is not general fixing of ini-
tially broken MS-DOS file timestamp idea but keeping the same timestamps
between FreeBSD MS-DOS file system and MS-DOS operating system installed
on the same machine. If the file /etc/wall_cmos_clock exists, it means
that CMOS clock keeps local time (MS-DOS and MS-Windows compatible mode).
If that file does not exist, it means that the CMOS clock keeps UTC time.
Adjkerntz passes this state to the machdep.wall_cmos_clock kernel vari-
of course...it would be *much* nicer if windows could just be told to
leave cmos time in utc.
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