Google is bringing Fuchsia OS to Android devices, but not in the way you might think

Google is responsible for developing two of the world’s most popular consumer-focused operating systems: Android and Chrome OS. But behind the scenes, it’s actually running on a third operating system called Fuchsia OS. Ever since Fuchsia first reared its head, it has been the subject of much speculation, including theories and predictions that it will eventually replace Android. While that seems unlikely at this point in time, Google is continuing to test Fuchsia in new and interesting places. Recently, it has been working on building a stripped-down version of the OS that will run in a virtual machine on Android devices.

Fuchsia OS is an open source operating system, just like Android and Chrome OS. Unlike the latter two, however, Fuchsia is not built on top of the Linux kernel. Rather, it’s built on top of Zircon, which Google says is “composed of a kernel and a small set of user-space utilities, drivers, and libraries needed for core system functions like booting.” Zircon’s “microkernel-like architecture” allows Fuchsia to “reduce the amount of trusted code running on the system” to just a few essential functions, which can lead to improved security and stability due to a reduced amount of code very privileged compared to typical “monolithic” cores.

Rumors from mid-2018 suggested that Google had ambitious plans to port Fuchsia OS to smartphones, PCs, and smart home devices. While the supposed goal of eventually replacing Android and Chrome OS with Fuchsia still seems a long way off (if not canceled altogether), Google successfully launched the operating system on smart home devices, starting with the first-generation Nest Hub in 2021. The team then successfully updated the larger Nest Hub Max and the second-generation Nest Hub to Fuchsia OS, making them the second and third devices, respectively, to run the OS.

To evolve Fuchsia beyond smart home devices, Google has been working on projects such as Starnix to run unmodified Linux binaries on Fuchsia devices. Additionally, since the end of April this year, Google has been working on a new project called “microfuchsia” that aims to make Fuchsia bootable on existing devices through virtualization. Microfuchsia, according to Google, is a build of Fuchsia OS aimed at virtual machines and designed to be bootable in virtualization solutions such as QEMU and pKVM.

pKVM is the hypervisor for the Android Virtualization Framework (AVF), a feature that Google introduced in Android 13 on select devices. Google developed AVF and pKVM to securely run certain types of workloads in an isolated environment. To run these workloads, Google created a very stripped-down version of the Android operating system called “microdroid” that contains the bare minimum of basic Android services, tools, and libraries.

Although not confirmed, it is possible that Google intends for microfuchsia to be deployed and used in a similar way as microdroid. In other words, Google may intend for microfuchsia to handle tasks that the host operating system — in this case, Android — needs to run safely. Microdroid already serves this purpose, but it’s possible that microfuchsia could make things faster or more secure (or both).

Recently, patches were submitted to the Android Open Source Project (AOSP) that lay the groundwork for a new APEX file that will contain microfuchsia. APEX is the file format used by Project Mainline to package system components, and an APEX file is what holds all binaries related to AVF on supported Android devices. WHEREAS com.android.microfuchsia The APEX file is not yet available, the references to its existence in AOSP and the code found in the Fuchsia Gerrit are interesting enough in themselves.

We can only speculate now what Google plans to do with microfuchsia, but we’ll keep an eye out to see if this project actually takes off.