netbsd-7 on Old World hardware

[John Klos <john%ziaspace.com@localhost>]

Hi,

I have NetBSD 7 running on a Power Mac mini G4 and so far it runs well. I 
just upgraded a Power Mac 9600 from NetBSD 5.2 to NetBSD 7 and I'm seeing 
problems.

First, while running ntpd with a GPS_NMEA source along with a PPS source, 
the time changed to January 15th, 2083. I thought it was a fluke, but it 
happened thrice. For now I'm only using the PPS source in ntp.conf.

Next, I noticed that certain parts of lang/perl5 were failing on the Power 
Mac 9600 which compiled fine on the Mac mini G4, but they weren't failing 
reproducibly. The system, by the way, has not crashed in many, many years 
and gets heavy use, so it's quite unlikely there's a hardware issue.

Remembering that benchmarks/flops showed funny times on mac68k after 
upgrading to NetBSD 7, I tried that and got results like these:

   FLOPS C Program (Double Precision), V2.0 18 Dec 1992

   Module     Error        RunTime      MFLOPS
                            (usec)
     1             nan      0.0611    229.0215
     2             nan     -0.0000  -81454545.4629
     3     -5.0000e-01      0.0000  870399999.7237
     4     -8.6603e-01      0.0000  349090909.0703
     5     -6.9315e-01      0.0000  742400000.0281
     6     -2.5000e-01      0.0000  337454545.4346
     7      5.0020e+02      0.0000  1535999998.4211
     8             inf      0.0000  7680000019.3901

   Iterations      =          0
   NullTime (usec) =     0.0000
   MFLOPS(1)       = -126780952.3965
   MFLOPS(2)       =  2486.5105
   MFLOPS(3)       =  2388.3596
   MFLOPS(4)       = 597333333.3179


Both the binary from NetBSD 5.2 and the binary made using gcc 4.5.4 in 
NetBSD 7 have the same kinds of errors, but both binaries run just fine on 
the Mac mini G4.

Finally, I turned off ntpd and noticed that the time drifts about 17 or 18 
seconds per hour. This has nothing to do with powersave (tested it both 
with and without powersave enabled) and vaguely remember something being 
mentioned a while back about time drift.

Any ideas about what to check?

Thanks,
John Klos