Ubuntu on a Mac

With every copy of Ubuntu Unleashed 2013 Edition we include a DVD of Ubuntu 12.10. This is similar to what we have done with past editions. The contents of the DVD are identical to and taken from the main Ubuntu download page. In the past, this disc has been sufficient to boot live or install on either a Windows machine or a Mac. However, this time around, anyone putting the disc in a Mac will find that the machine will not boot from the disc.

Bummer. We didn’t discover this until after the book was printed, the DVDs were created and attached, and the book shipped. When I read through the install documentation for Ubuntu while doing the editing for the new edition of the book, I failed to see any note of there being a problem. In fact, as I looked today (20 December 2012), there is still no note of any special needs when using Apple Mac hardware on http://www.ubuntu.com/download/desktop or in the install instructions at http://www.ubuntu.com/download/help/install-desktop-latest.

I have found that there is a different install DVD image available for 64 bit Mac that anyone can download from http://releases.ubuntu.com/quantal/, but this is not mentioned anywhere else that I can find and is not available from the main download page. I found it by searching Google and discovering the problem is common and that a new iso was created to circumvent a Mac-specific issue (details below on the actual issue).

If you bought my book and own Mac hardware, I apologize for the inconvenience. The DVD attached to the book will not boot on your machine, but you can download the Mac image mentioned just above and it should work.

For those interested in the technical details of the problem, here is a high-level description.

In past years, computers used a BIOS, or Basic Input/Output System, to load some software necessary for the hardware to then read and load an operating system. The industry has been moving to the UEFI, or Unified Extensible Firmware Interface, which serves a similar purpose to a BIOS but communicates differently and with greater flexibility. Most UEFI software includes legacy support for BIOS services to ensure compatibility across a wide range of hardware. Linux supports UEFI, and as a result, so does Ubuntu.

Because the version of UEFI that is included with Mac hardware only has to support a very limited range of hardware, it does not include that BIOS legacy support (and perhaps other support). This means that Mac hardware using UEFI can not read the files from the disc that are needed to boot Ubuntu. This is a direct result of Apple making a decision to use only the parts of the UEFI standard that support their Apple hardware. While it is not my preference as a geek and tinkerer, it is a reasonable business decision as Apple seems to prefer to control the entire user experience so that everything will “just work” for their users. The downside is that it becomes difficult to use any hardware or software they do not produce or directly sanction. Booting any operating system that is not OS X on Mac hardware is a use case that Apple does not support, so it doesn’t work easily. The workaround is to download the Ubuntu-community-provided modified DVD image linked above and use it as it has received some modifications that enable the version of UEFI on this Mac hardware to recognize the DVD and allow Ubuntu to boot.