side project a part 2: booting xnu

darwinbuild is absolutely stellar. building xnu is more painless than I ever could've hoped for. however, the script I found to install a new kernel by fiddling with the open firmware boot-file variable didn't work so I spent most of the day trying to track that down. finally I resorted to just copying my new kernel to the default location. and now it seems that the boot-file arg is working properly, so who knows what voodoo was going on before. it's time to start patching.