What Makes Huawei’s HarmonyOS Different? Inside Its Kernel, Compiler, and Architecture

Since Huawei was banned, several U.S. companies, including Google, announced suspensions of cooperation, with Google pausing certain features for Huawei devices, drawing widespread media attention.

Huawei plans to launch its own HarmonyOS, aiming to bridge phones, tablets, PCs, wearables, and cars, potentially becoming a super‑system alongside iOS, Android, and Windows.

Rumors claimed a Hongmeng OS release on June 24 in Hong Kong, which Huawei later denied, but the OS launch is considered certain, especially after the April introduction of the Ark compiler, signaling the start of Huawei's independent operating system.

Based on Ark compiler materials, HarmonyOS is likely written in C and C++.

Key insights from the Ark compiler diagram:

HarmonyOS and the Ark compiler share the concept of writing apps directly in machine language, eliminating Android's ART virtual machine and compiling to native binary code; this yields faster execution but requires extensive static solutions and higher memory usage.

Developing apps in C/C++ raises the technical barrier for developers, making ecosystem building more challenging.

With its own chips and system foundation, Huawei could adopt a closed iOS‑like model, offering long‑term potential, though its primary focus on communications rather than smartphones limits full commitment.

Given Huawei's focus on communications, it may pursue an open‑source path, but convincing other phone manufacturers to adopt HarmonyOS remains a significant hurdle.

Predictable Outlook for HarmonyOS:

Other Chinese phone makers are unlikely to install or prioritize HarmonyOS unless Huawei relinquishes control.

Even if HarmonyOS supports Android apps, maintaining a balance between developer benefits and user experience is crucial for its survival.

HarmonyOS, Android, and iOS share UNIX ancestry, which was written in C, indicating HarmonyOS's core is also C‑based.

The development tools offered to app developers are likely Java.

HarmonyOS Composition

Huawei's HarmonyOS consists of four parts: Linux kernel, Kirin processor runtime library, compiler, and virtual machine.

Linux Kernel: Open‑source, maintained by the Linux kernel team, written in C, offering higher execution efficiency than C++.

Runtime Library: Built on Linux, it must be adapted for different processors (e.g., Kirin vs. Qualcomm), typically written in C.

Virtual Machine: Acts as a bridge between the OS and hardware, enabling cross‑platform compatibility and reducing development difficulty; the commonly used virtual machine is the Java Virtual Machine.

Compiler: Transforms Java code into machine code for the virtual machine or directly for hardware; Huawei's Ark compiler provides static compilation, improving app smoothness by about 60%.

Differences Between HarmonyOS and Android

Architecture: HarmonyOS uses a microkernel design, which is harder to develop but offers higher system stability, whereas Android relies on a monolithic (macro) kernel that is easier to develop but more prone to crashes.

Cross‑Platform Support: HarmonyOS supports phones, PCs, wearables, and smart home devices, aiming for a seamless, unified OS that remains compatible with all Android applications, similar to Google's Fuchsia project for the 5G and IoT era.

In summary, HarmonyOS’s lower layers (Linux kernel and runtime) are written in C, the virtual machine may use C or C++, and the developer environment is likely Java.