The YDL yaboot-1.3.10-1o appears to have support for Apple dual G5 superior to what is in yaboot-1.3.10-9. (ofboot has no support for sata_something, ybin reports that /dev/sda2 cannot be mapped back to OpenFirmware path).
How's yaboot 1.3.12-7 doing for you? Rawhide latest has: yaboot-1.3.12-7.ppc.rpm as a package
Later yaboot is working on fish (G5) in rawhide and other G5's. Closing