Arnd Bergman of (originally working at IBM, now with Linaro), one of the key ARM kernel maintainers, worked with others to move from machine numbers to using [http://www.devicetree.org Device Tree] to describe the attached hardware. This paved the way to move to a "Single zImage" - a kernel which could run on a variety of different devices by using data in a board-specific Device Tree Blob (DTB) to initialize the correct device drivers with the correct parameters for each device. This in turn has made it much easier for various distros (Fedora, Debian/Ubuntu, Mint, Gentoo, etc) to support a range of devices.