halt vs. poweroff; server_mode variable (kernel 2.6.10)
I have a G4 Cube, and I'm trying to set it up on an UPS such that it
will come back up when the power comes back on.
On ACPI PCs which remember the last commanded power state, it is
common to use 'halt' to bring the system down, and then let the UPS
pull power a certain number of seconds after the halt command was
issued. Because the ACPI BIOS wasn't told to shut the computer down,
the assumption is that the computer will come back on when power is
It looked like that's what would happen if I set server_mode=1 in
/proc/pmu/options and executed halt. But when I ran 'halt', it turned
off the power, just as though I had run 'poweroff'.
Does anyone have any experience getting server_mode to work?
Further investigation shows that the server_mode setting gets reset to
0 in pmu_shutdown(), and platforms/pmac_setup.c seems to assign the
same meaning to pmac_halt() and pmac_power_off(). Is there any sort of
"halt processor, but don't power off" mode? Or should I just change to
runlevel 1, make sure everything is mounted read-only, and wait?
$ cat /proc/cpuinfo
processor : 0
cpu : 7400, altivec supported
temperature : 27-29 C (uncalibrated)
clock : 450MHz
revision : 2.9 (pvr 000c 0209)
bogomips : 894.97
machine : PowerMac5,1
motherboard : PowerMac5,1 MacRISC2 MacRISC Power Macintosh
detected as : 68 (PowerMac G4 Cube)
pmac flags : 00000004
L2 cache : 1024K unified
memory : 512MB
pmac-generation : NewWorld
$ uname -a
Linux boxster 2.6.10-powerpc #1 Wed Feb 23 20:43:26 CET 2005 ppc GNU/Linux
(running a mixed testing/unstable system)
Any suggestions would be appreciated.
- Charles Lepple