Sparc systems by default use the framebuffer and often have two video
cards, e.g. for my Ultra 10: a "standard" ATI and a "professional"
Creator 3D card.
Problem always has been detecting which card was "active". Getting it
right frequently required users disabling one or the other.
IIUC the FRAMEBUFFER_CONSOLE_DETECT_PRIMARY config option was designed to
solve this problem and take the correct framebuffer based on firmware
settings.
However, I see that in current kernels this option is not enabled. Please
consider enabling it, at least for Sparc but possibly for other
architectures as well.