Running Ubuntu Linux Is Messy On The 2013 MacBook Air
Earlier this month, shortly after Intel announced their latest-generation Haswell processors, Apple rolled out their new 2013 MacBook Air laptops. From a hardware perspective, the new MacBook Airs are incredible. The 13-inch MacBook Air can get a 12-hour battery life with Intel Haswell CPU. The 11-inch model continues being an ultra portable computer and has excellent performance with its Core i5 Haswell processor and HD Graphics 5000. As soon as the Haswell MacBook Airs went on sale, I bought an 11-inch model for Linux testing. Ubuntu can be installed and run on the new Apple MacBook Air, but the experience is less than desirable.
Ubuntu 13.10 development daily ISOs were used for installing to the Apple MacBook Air. When booting the LiveCD on the 11-inch model, on some boots from the Live CD the GPU would hang with the hang-check timer elapsing. Other boots, however, worked just fine for the Haswell graphics marketed as HD Graphics 5000 for the Core i5 processor. On a good boot, I proceeded to install Ubuntu 13.10 with the Linux 3.9 kernel to the MacBook Air while still being able to dual-boot into OS X.
The tested Apple MacBook Air was the MD711LL/A model and sports an Intel Core i5 4250U "Haswell" processor with a base clock of 1.30GHz, 4GB of DDR3 system memory, a 120GB Apple SSD SD0128, Intel Haswell-ULT HD Graphics 5000, Intel Haswell audio, and Broadcom 802.11ac WiFi.
This year's MacBook Airs utilize a new PCI Express SSD. To some surprise, there were no issues in Linux being able to find and install to the new PCI-E SSD on the 11-inch MacBook Air. The installation went without a hitch. However, once the install was complete, the system didn't seem to see the Ubuntu 13.10 installation as an EFI boot option when holding down the alt/option key. When installing rEFIt, the open-source boot manager doesn't seem to work on the new Haswell MacBook Air as it wasn't to be seen either. However, when installing reFInd, a fork of reFIt, it was displayed at boot time and had no problems seeing the EFI-enabled Ubuntu Linux partition.
Perhaps the biggest issue in running Ubuntu Linux on the MacBook Air MD711LL/A is that the WiFi doesn't work out of the box. The new MacBook Airs support 802.11ac wireless, which is powered by a Broadcom 802.11ac chipset. In particular, a Broadcom 0x43a0. It's an 802.11ac Broadcom BCM4360 chipset being used for the wireless and there's no mainline Linux kernel driver. Fortunately, however, it turned out to be easier than anticipated to get up and running. If installing the bcmwl-kernel-source package on Ubuntu, the wireless will work! Or for users of other distributions, the driver source can be fetched from Launchpad. This is the code to the Broadcom 802.11 Linux STA wireless driver. The latest 6.30 driver series does work with the Linux 3.10 kernel, fortunately.
No wireless "out of the box" was the main issue with Ubuntu Linux on the new MacBook Air, since there's no wired Ethernet and thus an old USB 802.11g WiFi adapter had to be used for fetching this out-of-tree driver. Once the bcmwl driver was installed, wireless worked just fine during tests on the Linux 3.9 kernel.
As Phoronix tests have shown from an Intel Core i7 4770K "Haswell" CPU, the Linux 3.10 kernel offers nice performance improvements for the new Intel hardware. When trying to move from the current Linux 3.9 kernel in Ubuntu 13.10 to Linux 3.10 from Git source, unfortunately the MacBook Air doesn't want to boot on the Linux 3.10 kernel. The system seems to hang shortly after loading the initrd on 3.10-based kernels with no apparent error or other information, but I haven't devoted much time yet to debugging this issue and will try it on Linux 3.10 final in a few days time.