Oh awesome -

>0 > see set-dfs-low
>:
>set-dfs-low
>   pvr@ 10 rshift 8003 <> if
>     exit
>     else
>     hid1@ 1 1f 9 - lshift or hid1! 1 ms 4 1 gpio!
>     then
>   ; ok
>0 > see set-dfs-high
>:
>set-dfs-high
>   pvr@ 10 rshift 8003 <> if
>     exit
>     else
>     5 1 gpio! 1 ms hid1@ 1 1f 9 - lshift andc hid1!
>     then
>   ; ok

These check if the CPU ID is 8003 (MPC7447) and then set high low and high
dynamic frequency switching values. I'll look at these closer and see if
they work immediately. These might provide a quickie interface to switching
(the gpio! and hid! do store values to address locations that certainly
imply this).

Out of curiosity, reboot and drop into OF, then before booting do

dev /cpus/PowerPC,G4 set-dfs-high

and then boot into NetBSD. If it does work, you may not want to stay booted
that way, as heat may be a problem until something more formal is
implemented.

>0 > decimal dev /cpus/PowerPC,G4 .properties
>name                    PowerPC,G4
>
>device_type             cpu
>reg                     00000000
>cpu-version             80030101

As Allen suspected, you've got a 7447A CPU, which has the dynamic frequency
switching.

>state                   running
>clock-frequency         4f790d50
>>bus-frequency           09eb18ef
>config-bus-frequency    09ef21aa
>timebase-frequency      01194000
>reservation-granule-size00000020
>
>[cut]
>
>processor-to-bus-ratio*200000010
>rounded-clock-frequency 4f5572c0
>recalced-clock-frequency4f58c778
>dynamic-power-step
>
>[...]
>
>this is it... i hope i haven't made mistakes... and sorry for the long
>thread :-)

I'll look at these some more. Quite fascinating, and thank you for the
effort :-)

tim