Introduction

What This Book Covers¶

65 chapters organized bottom-to-top through the Android architecture:

Part	Ch.	Topics
I	0	Frontmatter
I	1	Introduction
I	2	Source Code & Build System (Soong/Bazel/Kleaf)
I	3	Feature Flags (aconfig)
II	4	Boot and Init
II	5	Kernel (GKI)
II	6	System Properties
III	7	Bionic & Linker
III	8	Memory Management
III	9	Binder IPC
III	10	HAL (HIDL/AIDL)
III	11	NDK
IV	12	Native Services
IV	13	Graphics & Render Pipeline (OpenGL ES/Vulkan/Skia/HWUI)
IV	14	Animation System
IV	15	Audio System (Spatial)
IV	16	Media & Camera
IV	17	Sensors
V	18	ART Runtime
V	19	Native Bridge (Berberis)
VI	20	system_server
VI	21	Intent System
VI	22	Activity & Window Management
VI	23	Window System
VI	24	Display System
VI	25	View System
VII	26	Package Manager
VII	27	Content Providers
VII	28	Notifications
VII	29	Power Management
VII	30	Background Tasks
VII	31	Multi-User
VII	32	Account & Sync
VII	33	Location
VII	34	Storage
VIII	35	Networking (VCN/Thread)
VIII	36	Telephony (IMS)
VIII	37	Bluetooth
VIII	38	NFC
VIII	39	USB & ADB
IX	40	Security (TEE/Trusty)
IX	41	Credential Manager
IX	42	DRM
X	43	Widgets & RemoteViews (RemoteCompose)
X	44	WebView
X	45	Accessibility
X	46	Internationalization
XI	47	SystemUI (Monet/Keyguard)
XI	48	Launcher3
XI	49	Settings
XII	50	AI & AppFunctions (Computer Control)
XII	51	Companion & Virtual Devices
XIII	52	Mainline Modules (APEX)
XIII	53	OTA Updates
XIII	54	Virtualization (pKVM/crosvm)
XIII	55	Testing (CTS/VTS/Ravenwood)
XIII	56	Debugging Tools (Perfetto)
XIV	57	Architecture Support (ARM/x86/RISC-V)
XIV	58	Emulator
XIV	59	Device Policy
XIV	60	Automotive/TV/Wear
XIV	61	Print Services
XIV	62	Camera2 Pipeline
XV	63	Custom ROM Guide (step-by-step)
XV	64	Running Windows Games on Android
App.	A	Key Files Reference
App.	B	Glossary
App.	C	Why Kotlin Isn't on the Public API

License¶

This book is licensed under the Apache License 2.0, matching the license of the Android Open Source Project it analyzes. See the LICENSE file for details.

How to Navigate¶

Use the sidebar to browse chapters organized bottom-to-top through the Android architecture. Each chapter is self-contained but builds on previous ones.

Architecture Overview¶

graph TB
    subgraph "Part I-III: Foundation"
        BUILD[Build System] --> BOOT[Boot/Init]
        BOOT --> KERNEL[Kernel]
        KERNEL --> BIONIC[Bionic/Linker]
        BIONIC --> BINDER[Binder IPC]
        BINDER --> HAL[HAL]
    end
    subgraph "Part IV-V: Services & Runtime"
        HAL --> NATIVE[Native Services]
        NATIVE --> ART[ART Runtime]
    end
    subgraph "Part VI-VII: Framework"
        ART --> SYSTEM[system_server]
        SYSTEM --> WMS[Window/Display]
        SYSTEM --> PMS[Package Manager]
        SYSTEM --> SERVICES[Framework Services]
    end
    subgraph "Part VIII-XII: Features"
        SERVICES --> CONNECTIVITY[Connectivity]
        SERVICES --> SECURITY[Security]
        SERVICES --> UI[UI Framework]
        SERVICES --> APPS[System Apps]
        SERVICES --> AI[AI/ML]
    end
    subgraph "Part XIII-XV: Platform"
        APPS --> INFRA[Infrastructure]
        INFRA --> DEVICES[Device Support]
        DEVICES --> ROM[Custom ROM]
    end

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