PowerBook G4
I'm running Debian squeeze on a 12" PowerBook G4 and these are some of my notes about the configuration. This is may not work for your hardware so take with a grain of salt.
Hardware
CPU Info
cat /proc/cpuinfo
processor : 0
cpu : 7447A, altivec supported
clock : 1333.333000MHz
revision : 1.1 (pvr 8003 0101)
bogomips : 73.72
timebase : 18432000
platform : PowerMac
model : PowerBook6,4
machine : PowerBook6,4
motherboard : PowerBook6,4 MacRISC3 Power Macintosh
detected as : 287 (PowerBook G4 12")
pmac flags : 0000001a
L2 cache : 512K unified
pmac-generation : NewWorld
Memory : 768 MB
Ethernet
lspci | grep Ethernet
0002:20:0f.0 Ethernet controller: Apple Inc. UniNorth 2 GMAC (Sun GEM) (rev 80)
WLAN
lspci | grep Wireless
0001:10:12.0 Network controller: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller (rev 03)
Framebuffer
lspci | grep VGA
0000:00:10.0 VGA compatible controller: NVIDIA Corporation NV34M [GeForce FX Go5200] (rev a1)
Sound
For some reason or another after installation the snd-aoa driver is the standard driver on the machine. But there is not a single sound escaping the speakers with that driver. As written on the page of the snd-aoa driver the machine in quesiton PowerMac6,4 is not on the list of the supported Macs anyways.
I had to do a bit of fiddling by blacklisting the snd-aoa drivers and manually loading the snd-powermac one.
Firstly we add the snd-powermac to /etc/modules. Each module defined in the /etc/module file will be loaded at boot time.
echo snd-powermac >> /etc/modules
And confirming
grep snd-powermac /etc/modules
snd-powermac
Next is to blacklist the snd-aoa modules in /etc/modprobe.d/alsa-base-blacklist.conf
grep --color snd-aoa /etc/modprobe.d/alsa-base-blacklist.conf blacklist snd-aoa-i2sbus blacklist snd-aoa-soundbus blacklist snd-aoa-codec-toonie blacklist snd-aoa-codec-tas blacklist snd-aoa-codec-onyx blacklist snd-aoa-fabric-layout blacklist snd-aoa
After the next reboot sound should work fully.