How Mac OS X saves disk names...

Okay, so to reproduce a bug, I had to replace Helvetica with another font. My friend Flo grabbed a font with a name of the same length and just did a search-and-replace, and I dropped that in ~/Library/Fonts and I started testing.

A while later I restarted my Mac to boot into another OS version, and the following sight greeted me (sorry, quick cell phone snapshot):

Interesting. The startup selector somehow uses the font on the partition. Or, more likely, the (installed) OS renders the disk name into an image file somewhere, using its own font, and that's what the OS X startup selector uses to actually display it, because I don't think anyone would bother adding a whole TrueType rendering engine to EFI, plus make it look up the Helvetica font from each startup drive separately.

Anyone know how this actually works?

Reader Comments: (RSS Feed)

Drew Thaler writes: The OS renders the disk name into an image. /usr/sbin/bless --label is one way to change it. The code to do it is even available in Darwin: http://www.opensource.apple.com/darwinsource/10.5.2/bless-63/libbless/Misc/BLGenerateOFLabel.c

Qwerty Denzel writes: I too have wondered how this works, since it not only has to draw the text, images, and the transparent graphics, but it also has retrieve the icons and names somehow for the volumes. Surely what's even stranger is that it is using a font that you put it your user library, not the system or 'local' ones.

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