Comment Left out the most relevant part of the story! (Score 3, Informative) 44
The most relevant part of this story is that it is incredibly easy for Google to do this kind of porting because THEY RUN LINUX.
Linux reliably supports these multiple architectures so easily that many major distributions have x86 and ARM versions ready for download.
Big internet companies have made so much money over the last two decades running Linux that it boggles the mind.