Hibernation (suspend-to-ram) on iMac G4 with Debian Squeeze

[e20100633 <e20100633@gmail.com>]

Hello,

First, I apologize for my english but it is not my native language.

I successfully installed Debian Squeeze (kernel 2.6.32-5-powerpc) on a 
iMac G4. This is my first installation of Debian on a Apple desktop 
computer. I have few question about it. The first one is about 
hibernation (suspend-to-ram). I am unable to do it at all.

I'm trying to do it with pm-suspend; but the command doesn't do anything 
and return no errors (even in /var/log/{messages|syslog}). After some 
research I found that I may not have suspend-to-ram:

  # echo -n mem > /sys/power/state
  bash: echo: write error: No such device
  # cat /sys/power/state
  disk

Plus, trying with hal-system-power-pmu return an error too:

  /usr/lib/hal# ./hal-system-power-pmu sleep
  power-pmu : PMU_IOC_SLEEP failed

I believe that suspend-to-ram is supposed to work out of the box on 
Debian stable with my good old powerpc. So I was thinking that I forgot 
the installation of some package maybe? I search debian repos with 
apt-cache search but nothing relevant seems to be here.

Can someone please help me? I don't know what research I can do.
Thank you by advance.

Regards.

e-

Addendum: some possible usefull informations:

# lspci
000:00:0b.0 Host bridge: Apple Computer Inc. UniNorth 2 AGP
0000:00:10.0 VGA compatible controller: nVidia Corporation NV18
   [GeForce4 MX with AGP8X (Mac)] (rev a2)
0001:10:0b.0 Host bridge: Apple Computer Inc. UniNorth 2 PCI
0001:10:17.0 Unassigned class [ff00]: Apple Computer Inc.
   KeyLargo/Intrepid Mac I/O
0001:10:18.0 USB Controller: Apple Computer Inc. KeyLargo/Intrepid USB
0001:10:19.0 USB Controller: Apple Computer Inc. KeyLargo/Intrepid USB
0001:10:1a.0 USB Controller: Apple Computer Inc. KeyLargo/Intrepid USB
0002:20:0b.0 Host bridge: Apple Computer Inc. UniNorth 2 Internal PCI
0002:20:0d.0 Unassigned class [ff00]: Apple Computer Inc.
   UniNorth/Intrepid ATA/100
0002:20:0e.0 FireWire (IEEE 1394): Apple Computer Inc. UniNorth 2
   FireWire (rev 81)
0002:20:0f.0 Ethernet controller: Apple Computer Inc. UniNorth 2 GMAC
   (Sun GEM) (rev 80)

# cat /proc/cpuinfo
processor	: 0
cpu		: 7455, altivec supported
clock		: 999.999997MHz
revision	: 3.3 (pvr 8001 0303)
bogomips	: 66.56
timebase	: 33280414
platform	: PowerMac
model		: PowerMac6,1
machine		: PowerMac6,1
motherboard	: PowerMac6,1 MacRISC3 Power Macintosh
detected as	: 287 (Flat panel iMac)
pmac flags	: 00000010
L2 cache	: 256K unified
pmac-generation	: NewWorld
Memory		: 1024 MB