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diff --git a/share/man/man9/inittodr.9 b/share/man/man9/inittodr.9 new file mode 100644 index 000000000000..61524f206296 --- /dev/null +++ b/share/man/man9/inittodr.9 @@ -0,0 +1,123 @@ +.\" $NetBSD: inittodr.9,v 1.2 1996/03/27 21:16:06 jtc Exp $ +.\" +.\" Copyright (c) 1994 Christopher G. Demetriou +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by Christopher G. Demetriou +.\" for the NetBSD Project. +.\" 3. The name of the author may not be used to endorse or promote products +.\" derived from this software without specific prior written permission +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd March 22, 1997 +.Dt INITTODR 9 +.Os +.Sh NAME +.Nm inittodr +.Nd initialize system time +.Sh SYNOPSIS +.In sys/types.h +.In sys/systm.h +.Ft void +.Fn inittodr "time_t base" +.Sh DESCRIPTION +The +.Fn inittodr +function determines the time and sets the system clock. +It tries to pick the correct time using a set of heuristics that examine +the system's battery backed clock and the time obtained from the root +file system, as given in +.Fa base . +How the +.Fa base +value is obtained will vary depending on the +root file system type. +The heuristics used include: +.Bl -bullet +.It +If the battery-backed clock has a valid time, it is used. +.\" .It +.\" If the battery-backed clock does not have a valid time, and +.\" the time provided in +.\" .Fa base +.\" is within reason, +.\" .Fa base +.\" is used as the current time. +.\" .It +.\" If the battery-backed clock appears invalid, and +.\" .Fa base +.\" appears non-sensical or was not provided (was given as zero), +.\" a arbitrary base (typically some time in the late 1970s) +.\" will be used. +.It +If the battery-backed clock does not have a valid time, +the time provided in +.Fa base +will be used. +.El +.Pp +Once a system time has been determined, it is stored in the +.Va time +variable. +.Sh DIAGNOSTICS +The +.Fn inittodr +function prints diagnostic messages if it has trouble figuring +out the system time. +Conditions that can cause diagnostic messages to be printed include: +.Bl -bullet +.It +The battery-backed clock's time appears nonsensical. +.\" .It +.\" The +.\" .Fa base +.\" time appears nonsensical. +.\" .It +.\" The +.\" .Fa base +.\" time and the battery-backed clock's time differ by a large amount. +.El +.Sh SEE ALSO +.Xr resettodr 9 , +.Xr time 9 +.Sh BUGS +On many systems, +.Fn inittodr +has to convert from +a time expressed in terms of year, month, day, hours, minutes, +and seconds to +.Va time , +expressed in seconds. +Many of the implementations could share code, but do not. +.Pp +Each system's heuristics for picking the correct time are slightly +different. +.Pp +The +.Fx +implementation should do a better job of validating the time provided in +.Fa base +when the battery-backed clock is unusable. +Currently it unconditionally sets the system clock to this value. |