NOTE: rpiboot doesn't actually work on recent OS X versions and/or Macs due to a bug in the RPi0/RPi1 chipset: https://www.raspberrypi.org/forums/viewtopic.php?f=98&t=90825
These instructions compile a native OS X version of rpiboot that lives in your home directory, and which cannot be moved around, but should always be discoverable by applications.
Assumes OS X with Xcode or Xcode command-line tools, not macports or homebrew
To install Xcode command-line tools in recent versions of OS X, open Terminal, type xcode-select --install
and click "Install"
Older versions of OS X may need to manually download disk images of older versions of Xcode and/or the Xcode command-line tools, as various certificates may have expired (e.g. 10.7.4 requires a manual install from the Xcode 4.6.2 command-line tools image)