Installing Linux on a Mac Mini without OSX

[Brian Sammon <debian-users-list@brisammon.fastmail.fm>]

I was recently given a Mac Mini (Intel Mid 2007) that had been wiped.

I tried to install Debian (Wheezy) on it, and the installer reported success, but 
when it came time to eject and reboot, Debian didn't boot from the hard drive.

Googling finds me various pages about installing Linux where one of the steps is something like "Boot into OSX"

Is there a way to install Debian/Linux on this machine that doesn't involve buying or borrowing (or "borrowing") a copy of OSX?  Is it easier to install linux on a USB disk and run it off of that?

Two particular subtasks that I may need to do that seem to require OSX:
1) "Blessing" a partition
2) Checking what version of firmware it has (some versions have BIOS
   compatibility)

Any pointers/suggestions?

I'm also looking into PureDarwin as a possible solution.