building images for running from flash

[Z.C.B.]

Just been looking at rebuilding my router. I understand building the
image and etc, but the issue I am running into is what to do about
ports. To solve this, I am looking at building the image and using
mdconfig, unionfs, and jail to solve building ports. Also looking
at the possibility of qemu. Any thoughts or suggestions?

Another annoying issue is the muckery involved with /etc/make.conf...
The issue I am running into that is the CPUTYPE? option is different
for the build machine and router that the flash will be used on. Any
nice way to deal with this?