Beyond HIDL: Modernizing Android HALs with Rust & Stable AIDL

Android is transitioning from HIDL to Stable AIDL to improve HAL interface stability and long-term maintainability. However, many production devices still depend on legacy HIDL implementations, making upgrades difficult.

This talk presents a migration of a HAL from HIDL to Stable AIDL, focusing on real-world challenges. It covers key differences in interface definition, versioning, Binder IPC, and VINTF compatibility. The session walks through a step-by-step migration: rewriting interfaces, updating services, and modifying manifests.

Hands-on guide for engineers who must modernize existing HIDL HALs to Stable AIDL in shipping devices.

As Android continues adopting Rust to improve security and reliability, platform developers are gaining new ways to build safer system components. This talk introduces Android Hardware Abstraction Layers (HALs) developed using Rust and AIDL, covering how Rust integrates with AOSP, Binder IPC, and modern Android architecture.

Through a practical example, attendees will learn how to create and integrate a Rust-based HAL, understand the benefits of memory safety, and explore why Rust is becoming an important part of Android's future.

1. Explain the core architectural differences between HIDL and AIDL in the Android HAL stack.
2. List the Android version milestones that make AIDL mandatory for new and production devices.
3. Execute a step-by-step HIDL → AIDL migration for a real hardware interface.
4. Address SELinux policy changes, VINTF manifest updates, and compatibility matrix versioning required by the migration.
5. Identify and mitigate common failure, validation.
6. Understand why Android is adopting Rust for system-level development.
7. Explain how AIDL-based HALs fit into the modern Android architecture.
8. Create and integrate a Rust-based HAL in AOSP.
9. Implement Binder IPC communication between Android services and Rust HALs.
10. Identify common challenges when developing and debugging Rust HAL services.