The UDOO X86 is an x86 based system: https://www.udoo.org/udoo-x86/ Some applications are available on both architectures, as separate downloads. What application would you like to run?
The Unity editor is only available on the following platforms: Windows 7 SP1+, 8, 10, 64-bit versions only; Mac OS X 10.9+ https://unity3d.com/get-unity/download