I just did a git pull today to this commit:
Merge: c728876 21a4d96
Author: Peter Maydell <peter.maydell(a)linaro.org>
Date: Fri Jun 24 11:00:15 2016 +0100
When I tried to run qemu-system-ppc with and without the -bios option, all
I see is a empty black window. Switching consoles yields a Guest hasn't
initialized the display yet message. Are you having better luck or is this
a known issue?