lubuntu 14.04 ppc - graphics problem

[farinet at arcor.de]

Finally i got the ppc live-cd to work: But the graphics are heavvily
messed up. Some windows - network manager e.g. - seems transparent and
empty. Moving the windows is slow etc. And the cpu is working all time
at 100% (therefore the fan is on and loud too!).

I'm sure that's related to the video driver. Is there a setting i could
put in to yaboot "on the fly" to hopefully correct/stabilize the
display. The graphic card of the machine is a RV350/M10 (i think that's
the same like a Radeon960/M10)

Moreover, during the boot, i noticed there is a problem with the
broadcom driver but i couldn't read the msg exactly. In any case
something like: kernel modules for broadcom legacy ar missing.

TIA for any pointer.