I wrote this 7 years ago, in 2009:
Until ARM comes up with a full computer instead of just a CPU, it's no contender in Linux server space.
The final question had to do with cross-platform drivers. There is an interpreted executable format known as EFI Byte Code (EBC); drivers compiled to that format can run on multiple architectures. [...]
Graf asked whether drivers could, instead, be shipped as a multiple-architecture binary. Progress is being made in this direction, and EFI supports multiple binary formats.
P.S. Jon reminded me about SBSA, and indeed it's a solid advancement. But using EFI drivers is an idea so monstrously dumb that I don't even know what to say.