[phlo]

Most current smartphones are ARMv7, Apple's A7 stands out as a(n albeit slower) ARMv8 SoC. I'm not quite sure about the compatibility between the two, but at least iPhones 5/5C should be architecturally compatible.

Performance might be questionable, as current Android phones tend to be quad-core models clocked around 2 GHz while A6/A7 feature only two cores at around 1.3-1.4 GHz.

[sp332]

It's not just the CPU, they would have to provide Android drivers for networking, bluetooth, cameras, etc. ARM platforms aren't standardized like PCs.

[bentcorner]

I feel like it's almost a quirk of history that the PC has become home to so many different operating systems.

Hardware platforms that allow me to swap software on them are very few and far between. The fact that PCs were like this over 20 years ago and continue to be so to this day is amazing.

It's a shame that phone hardware didn't follow the same path. Android's openness (for varying levels of "open") is great and all, but I'm more interested in hardware openness. The Nexus line seems to be the current leader in openness + consumer availability + quality, but it's a shame there aren't more.