With the introduction of Android 5 (Lollipop), the 64-bit hardware architecture is available for both ARM and Intel platforms. However, 64-bit hardware devices for Android were still under development at that time. The only choice for developers was to get a hardware reference platform from silicon vendors.
To help developers test their applications on 64-bit architecture, the engineers at Linaro did an excellent job enabling a virtual hardware platform on QEMU to test ARMv8-A 64-bit architecture. They gave this virtual hardware platform a code name, ranchu. You may refer to the blog at Linaro by Alex Bennée at https://www.linaro.org/blog/core-dump/running-64bit-android-l-qemu/.
This change was adopted by Google later ...
