Unfortunately this is not a perfect world and there, as always, some restrictions that you should be aware of.
MILO is not meant to load operating systems other than Linux, although it can load images linked to run at the same place in memory as Linux (which is 0xFFFFFC0000310000). This is how the flash management utilities can be run.
The PALcode sources included in miniboot/palcode/blah are
correct, however there are problems when they are built using the
latest gas. They do build if you use the ancient a.out gas
that's supplied in the Alpha Evaluation Board toolset (and that's how
they were built). I'm trying to get someone to fix the new gas.
Meanwhile, as a workaround, I have provided pre-built PALcode for the
supported boards and David Mosberger-Tang has a fixed gas on
his ftp site.