Broadcom BCM5719 libre firmware coming real soon

Posting from the Southern Hemisphere today, kudos to reader Mark J who sent in a heads-up on the progress the Ortega project has done on reverse-engineering the Broadcom BCM5719's firmware. If that number sounds familiar, it's because it's the very same NIC in the Talos II and Blackbird (see a photograph) and one of the few places left in the Talos family that binary blobs are required. Apparently, the reverse engineering effort is now believed sufficient to create a clean-room implementation.

And where is that implementation? Why, on Github, of course. As of this writing the current firmware is a work in progress, but now that the chip is much better understood it's very likely work will move much more quickly.

The BCM5719 is an interesting chip internally, implementing MIPS II (!) cores that apparently were once part of the receive and transmit machinery but are now mostly relegated to autoconfiguration-like tasks. A MIPS core exists for each port, but only a single application processor engine (APE) is present per chip. Hugo Landau's work on figuring out how to talk to the APE, the most essential component any open-source driver would need to interface with as it implements the sideband interface, is nothing short of heroic. A particularly noteworthy deficiency he discovered was that even though the firmware image for the APE's ARM Cortex-M3 has an RSA signature, nothing actually checks it! That would seem like a terrible rookie mistake on Broadcom's part but it's great news for us. A hearty congratulations to everyone's hard work on a very necessary project.