A few months ago Intel announced that it had completed work on a 64-bit version of the Linux kernel for use with Android on Intel processors. The 64-bit kernel is used by Android at the lowest level to interface with the hardware and perform functions like processes scheduling and memory management. That was for the x86-64 architecture. Now Linaro, a not-for-profit engineering organization that focuses on developing Linux and open source technologies for ARM processors, has started building 64-bit Linux kernels for Android on ARM.
Android has several different layers. At the top are the apps and games that third party developers write. Supporting these apps and games is a series of frameworks and libraries including the Java Virtual Machine (Dalvik or ART). At the lowest level is the kernel. As well as handling process scheduling and memory management, the Linux kernel is the home to things like the networking stack and the various drivers.
Linaro has started testing the 64-bit kernel with the 32-bit version of Android 4.4 KitKat on real 64-bit hardware. Although not yet available in consumer devices, several companies like Qualcomm and Marvell have announced plans to release 64-bit processors and these companies along with others like Nvidia and AMD probably have engineering samples available which they have lent to Linaro.
While the kernel on Intel and ARM processors is now 64-bit, the conversion of the rest of the layers from 32- to 64-bit is Google’s responsibility. Google hasn’t made any public announcements about how and when it plans to release a 64-bit version of Android. The company has several options open to it. The search giant could release a 32 bit version of Android with a 64-bit kernel, or it could release a pure 64-bit version where every part of the system including the Java Virtual Machine is 64-bit.
It is rumored that Google could announce a 64-bit version of Android at its I/O conference in late June. Google are certainly under pressure from chip-makers like Qualcomm, and from handset makers like Samsung, to create a 64-bit version of Android to coincide with the next generation of processors and the smartphones which will use them.