Use debian as a base, you can install any linux distribution which support installation by chroot, so for example, it's very easy to install ubuntu and gentoo in this fashion. I have all three running externally using bootos 2.01 for Kmeaw's CFW 3.55.
I don't know if there is a base for yellowdog that one could use to do chroot installation. I have tried to copy the yellowdog iso to an external HDD partition, and boot the relevant image to start the installation, but I ran into some problems similar to some guys experienced years ago on the ps3 which still supported linux (so definitely not a new issue), it's basically anaconda's python script problem, it just could not pass the dependency check. So I am burning the YDL dvd and try again. Knock on the wood.
In the meantime, if anyone has any information on how to get the YDL root filesystem (something similar to gentoo's stage3 binary), we could do an easy installation of YDL, providing that you have already at least one linux installation working. Please leave me a note here.
[edit]: No, DVD installation still ran into the same error.
[edit2]: Yea, Yippie, I got it working, I made a small mistake, upon examining the debug log, I see something like this: File "/usr/lib/anaconda/fsset.py" , line 550, raise SystemError. Well, I don't know what is fsset.yy, but from the name, sounds like filesystem setup, well, I just realized that the external partition I have been using to install YDL to was formated as ext4, but YDL only supports ext2/ext3, so as a last try, I allow YDL installer to format it as ext3, and bingo, no more errors. Now it's installing, will update here when I'm done. I think this also means I probably did not have to burn the DVD after all, but hey, you never knew ahead until you found a solution.
[edit3]: After some 748 packages installation, I got YDL 6.2 running. Of course, I have to use my customized kernel, but it's working.