iic/i2c debugging on PowerMac

[Andreas Tobler]

Hi,

I'm trying to access (read/write) an i2c device on my G5. The problem 
is, I do not know the right i2c address although I have it from the 
device-tree, it's 0x15e.

I read about the i2c utilitiy which requires the iic driver compiled 
into the kernel. Done that and it seems it is there:

unin0
     iichb0 pnpinfo name=i2c compat=keywest-i2c
       iicbus0
         iic0 at addr=0
         fcu0 pnpinfo name=fan compat=fcu at addr=0x15e

But I do not have this device entry in /dev. Trying to create one does 
not work.
mknod /dev/iic0 c 103 0
mknod: /dev/iic0: No such file or directory

This is a netboot environment, might this be the cause of not being able 
to create the device?
Or do I have another issue?

Has anyone experience with iic buses on PowerMac or hints on debug 
techniques?

TIA,

Andreas