[ebenupton]

That's not correct. The code that's been released is for BCM21553, which doesn't have a VPU. There are bits and pieces of VPU assembler in there, but they're unused on the ARM target. The intention is that people port this (ARM-based) drop to run on the ARM on BCM2835. No reverse engineering required.

[makomk]

Ah, that makes more sense, thanks! There's an awful lot of vestigial VPU-related stuff lying around the source tree, including what I'm guessing are the unused remnants of a dead build system...