At OLPC we need to support ext3 and jffs2 builds even more so than livecd isos. Since most of the process is the same up until the final image and bootloaders we would like to add this support into the livecd tools so that all fedora projects use one toolchain. The question is how can this best be accomplished?
I think passing a --variant switch (i.e. --variant=jffs2) should switch the backend to generating the correct image. This also requires template support and the ability to select templates to write out based on the variant in the %post. For instance the olpc.fth file is read in by the openfirmware. For jffs2 builds we point to the nand on the XO machines. For ext3 we point to a USB disk. Also on ext3 we write out grub entries for use with standard machines and vitalization software like qemu.
What would be the best way to add this support to the livecd tools?