Patch Name:  PHKL_4412

Patch Description: s700 9.01 correct hardware clock drift problem

Changes to hardclock() to check the system clock against the TOD clock every
10 minutes, and adjust itick_per_tick as necessary to keep them in sync.

Compensates for hardware problems on certain S700 workstations, whereby
the calibration value generated at boot time is inacurrate, causing the
system clock to drift.  This patch incorporates code into hardclock()
so that the system clock will be checked against the TOD (time of day)
clock every 10 minutes, and if there is any discrepancy, the value of
itick_per_tick will be adjusted to drift the system clock back in sync
with the TOD clock.  This assumes that the TOD clock (which is generally
a free-running battery-powered clock) is more accurrate than the system
clock (which is based on the CPU crystal).

In most cases, workstations' CPU crystal has roughly the same tolerances
as the TOD clock, so it would make no sense to sync one to the other.
These tolerances should keep the system clock within about 4 seconds/day
of the correct time.  However, for some systems, the clock calibration
generated by the hardware at boot time has been found to be intermittently
inaccurrate, causing larger system clock drifts (over 30 seconds/day).
This patch should only be applied to systems showing this larger system-clock
drift.

Path Name:  /hp-ux_patches/s700/9.X/PHKL_4412

Effective Date:  940621

OS Release:  9.01

Reboot Required:  Yes

Patch Files:  
/system/PHKL_4412/new/kern_clock.o

SR#:  5003191239

"what" string/timestamp:  
kern_clock.o:
        kern_clock.c$Revision: 1.46.81.5 $$Date: 94/08/04 19:44:14 $PATCH_9.01
 (PHKL_4412)


"sum" output:  
30215 23 kern_clock.o


Dependencies:  None

Supersedes:  None

Patch Package Size:  72 Kbytes

Installation Instructions:  

     Please review all instructions and the Hewlett-Packard
     SupportLine User Guide or your Hewlett-Packard support terms
     and conditions for precautions, scope of license,
     restrictions, and, limitation of liability and warranties,
     before installing this patch.

     Note: Please back up your system before you patch.

---------------------------------------------------------------------------
After getting the patch onto your machine, unshar the patch (sh PHKL_4412).

To install this patch do the following:
1) Run /etc/update (Note: you must be logged in as root to update
   a system).
2) Once in the update "Main Menu" move the highlighted line to "Change
   Source or Destination ->" and press "Return" or "Select Item".
3) Make sure the highlighted item in the "Change Source or Destination"
   window is "From Tape Device to Local System ...", then press "Return" or
   "Select Item".
4) You should now be in the "From Tape Device to Local System" window.
   Change the "Source:  /dev/rmt/0m" to "Source: /tmp/PHKL_4412.updt"
   (this assumes that you are in the /tmp directory where PHKL_4412.updt
   has been placed).  Note: You must enter the complete path name.
5) Press "Done".
6) From here on follow the standard directions for update.

The customized script that update runs will move the original software
to /system/PHKL_4412/orig.  HP recommends keeping this software there in
order to recover from any potential problems.  It is also recommended that
you move the PHKL_4412.text file to /system/PHKL_4412 to be retained for
future reference.

If you wish to put this patch on a magnetic tape and update from the tape
drive, dd a copy of the patch to the tape drive.  As an example the
following will create a copy of the patch that update can read:
dd if=PHKL_4412.updt of=/dev/rmt/0m bs=2048