Fear and Loathing in Les Rambles/ blog/ My CuBox-i has arrived

A couple of weeks ago, Gunnar Wolf mentioned on IRC that his CuBox-i4 had arrived. This resulted in various jealous noises from me; having heard about this device making the rounds at the Kernel Summit, I ordered one for myself back in December, as part of the long-delayed HDification of our home entertainment system and coinciding with the purchase of a new Samsung SmartTV. We've been running an Intel Coppermine Celeron for a decade as a MythTV frontend and encoder (hardware-assisted with a PVR-250), which is fine for SD video, but really doesn't cut it for anything HD. So after finally getting a TV that would showcase HD in all its glory, I figured it was time to upgrade from an S-Video-out, barely-limping-along tower machine to something more modern with HDMI out, eSATA, hardware video decoding, and whose biggest problem is it's so small that it threatens to get lost in the wiring!

Since placing the order, I've been bemused to find that the SmartTV is so smart that it has had a dramatic impact on how we consume media; between that and our decision to not be a boiled frog in the face of DISH Network's annual price increase, the MythTV frontend has become a much less important part of our entertainment center, well before I ever got a chance to lay hands on the intended replacement hardware. But that's a topic for another day.

Anyway, the CuBox-i4 finally arrived in the mail on Friday, so of course I immediately needed to start hacking on it! Like Gunnar, who wrote last week about his own experience getting a "proper" Debian install on the box, I'm not content with running a binary distribution image prepared by some third party; I expect my hardware toys to run official distro packages assembled using official distro tools and, if at all possible, distributed on official distro images for a minimum of hassle.

Whereas Gunnar was willing to settle for using third-party binaries for the bootloader and kernel, however, I'm not inclined to do any such thing. And between my stint at Linaro a few years ago and the recent work on Ubuntu for phones, I do have a little knowledge of Linux on ARM (probably just enough to be dangerous), so I set to work trying to get the CuBox-i4 bootable with stock Debian unstable.

Being such a cutting-edge piece of hardware, that does pose some challenges. Support for the i.MX6 chip is in the process of being upstreamed to U-Boot, but the support for the CuBox-i devices isn't there yet, nor is the support for SPL on i.MX6 (which allows booting the variants of the CuBox-i with a single U-Boot build, instead of requiring a different bootloader build for each flavor). The CuBox-i U-Boot that SolidRun makes available (with source at github) is based on U-Boot 2013.10-rc4, so more than a full release behind Debian unstable, and the patches there don't apply to U-Boot 2014.01 without a bit of effort.

But if it's worth doing, it's worth doing right, so I've taken the time to rebase the CuBox-i patches on top of 2014.01, publishing the results of the rebase to my own github repository and submitting a bug to the Debian U-Boot maintainers requesting its inclusion.

The next step is to get a Debian kernel that not only works, but fully supports the hardware out of the box (a 3.13 generic arm kernel will boot on the machine, but little things like ethernet and hdmi don't work yet). I've created a page in the Debian wiki for tracking the status of this work.