NetBSD/sys/arch/mipsco/mipsco/clock.c
wdk 5656bdea79 Don't trust the realtime clock if the data is before 1988. This is
consistant with other ports.

Prevent uninitialized time from being written back to the RTC (1-Jan-1970)
if the machine is halted from the root device name prompt
(bootflags & RB_ASKNAME)
2000-08-29 10:34:13 +00:00

172 lines
5.2 KiB
C

/* $NetBSD: clock.c,v 1.2 2000/08/29 10:34:13 wdk Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department, Ralph Campbell, and Kazumasa Utashiro of
* Software Research Associates, Inc.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* from: Utah $Hdr: clock.c 1.18 91/01/21$
*
* @(#)clock.c 8.1 (Berkeley) 6/11/93
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <dev/clock_subr.h>
#include <machine/cpu.h>
#include <machine/autoconf.h>
#include <machine/mainboard.h>
#include <machine/sysconf.h>
void setstatclockrate __P((int));
void cpu_initclocks __P((void));
void inittodr __P((time_t));
void resettodr __P((void));
#define MINYEAR 1998 /* "today" */
/*
* Machine-dependent clock routines.
*
* Startrtclock restarts the real-time clock, which provides
* hardclock interrupts to kern_clock.c.
*
* Inittodr initializes the time of day hardware which provides
* date functions. Its primary function is to use some file
* system information in case the hardare clock lost state.
*
* Resettodr restores the time of day hardware after a time change.
*/
/*
* We assume newhz is either stathz or profhz, and that neither will
* change after being set up above. Could recalculate intervals here
* but that would be a drag.
*/
void
setstatclockrate(newhz)
int newhz;
{
}
/*
* Set up the real-time and statistics clocks. Leave stathz 0 only if
* no alternative timer is available.
*/
void
cpu_initclocks()
{
}
/*
* Initialze the time of day register, based on the time base which is, e.g.
* from a filesystem. Base provides the time to within six months,
* and the time of year clock (if any) provides the rest.
*/
void
inittodr(base)
time_t base;
{
struct clock_ymdhms dt;
int deltat, badbase = 0;
if (base < (MINYEAR-1970)*SECYR) {
printf("WARNING: preposterous time in file system\n");
/* read the system clock anyway */
base = 6*SECYR + 186*SECDAY + SECDAY/2;
badbase = 1;
}
(*platform.read_todr)(&dt);
/* simple sanity checks */
if (dt.dt_mon < 1 || dt.dt_mon > 12 ||
dt.dt_day < 1 || dt.dt_day > 31 ||
dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 59) {
printf("WARNING: preposterous clock chip time\n");
/*
* Believe the time in the file system for lack of
* anything better, resetting the TODR.
*/
time.tv_sec = base;
if (!badbase)
resettodr();
return;
}
/* now have days since Jan 1, 1970; the rest is easy... */
time.tv_sec = clock_ymdhms_to_secs(&dt);
if (!badbase) {
/*
* See if we gained/lost two or more days;
* if so, assume something is amiss.
*/
deltat = time.tv_sec - base;
if (deltat < 0)
deltat = -deltat;
if (deltat < 2 * SECDAY)
return;
printf("WARNING: clock %s %d days",
time.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
printf(" -- CHECK AND RESET THE DATE!\n");
}
}
/*
* Reset the TODR based on the time value; used when the TODR
* has a preposterous value and also when the time is reset
* by the stime system call. Also called when the TODR goes past
* TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
* to wrap the TODR around.
*/
void
resettodr()
{
struct clock_ymdhms dt;
if (time.tv_sec >= (MINYEAR-1970)*SECYR) {
clock_secs_to_ymdhms(time.tv_sec, &dt);
(*platform.write_todr)(&dt);
}
}