When we installed Linux on Intel's Haswell NUC, the biggest problem we encountered involved booting the computer after the install process was complete. We've been talking with Intel's NUC team since then, and in response to our problems, Intel has just issued BIOS version WY0024 for the Haswell-based NUC boxes. The update fixes, among other things, problems booting SteamOS and some other Debian-based distributions. The new firmware can be installed from within Windows or by putting the BIOS file on a USB drive and pressing F7 at boot to launch Intel's Flash Update Tool.

To recap briefly, UEFI-based systems all have a small partition on their hard drives where bootloader files are stored. These bootloaders, which usually have an .EFI file extension, direct the computer to begin loading the operating system from the drive's main OS partition. The problem with older NUC BIOSes is that they didn't always know where to look for Linux bootloader files. Linux distributions would install to the computer just fine, but by default the computer wouldn't be able to tell that the internal hard drive could boot the system, and you would have to manually move the bootloader file where the computer could find it. The NUC team tells us that further improvements to the boot process are coming, but this update appears to at least fix the problems that we had—Ubuntu, Mint, and SteamOS all install and boot just fine with the latest BIOS update installed.

In addition to the Linux fixes, the new BIOS addresses fan speed and hard disk password length issues, fixes a problem where the system would hang with certain USB drives attached, and tweaks a couple of things in the BIOS settings screens. You can read the full release notes here (PDF).