aosp-internal-book

AOSP Part XII — AI & Devices. Use when reasoning about on-device ML in AOSP, NNAPI, the AppFunctions framework for assistant integration, the Computer Control flow, CompanionDeviceManager, or virtual devices (virtual displays/inputs/cameras for cross-device experiences), or the NpuManager module for on-device neural accelerators (model-load admission control, the NDK ANpuBuffer surface, the android.hardware.npu HAL). Chapters 51–53.

AOSP Internals — Appendices. Use when looking up a key file path (per-chapter table of the most important AOSP source files: build, init, kernel, HAL, framework services, system apps, infrastructure) or the meaning of an AOSP-specific acronym/term (Treble, VINTF, GKI, APEX, AIDL, HIDL, etc.), why Kotlin is absent from the public API, or what changed from Android 16 to Android 17. Reference material — load when you need a concrete path, a definition, or a changelog rather than narrative explanation.

AOSP Part VIII — Connectivity. Use when reasoning about Networking (ConnectivityService, Wi-Fi framework, netd, DNS resolver, VPN, tethering, NetworkSecurityConfig, VCN, Thread mesh), Telephony (TelephonyManager, PhoneInterfaceManager, RIL/RILD, modem AIDL, IMS framework, emergency calling), Bluetooth (Bluetooth Mainline module, BTA, GATT, A2DP/HFP/AVDTP, LE Audio, pairing, scanning, advertising), NFC (NfcAdapter/NfcService, NCI, tag dispatch, HCE, secure element, reader mode, NFC-F/V), or USB & ADB (USB gadget framework, host-mode USB, MTP/PTP, RNDIS tethering, adb daemon, adb over Wi-Fi). Chapters 35–39.

AOSP Part XIV — Device Support. Use when reasoning about per-architecture support (ARM 32/64, x86_64, RISC-V, ABI matrix, toolchains), the QEMU-based Android emulator (AVD format, hardware acceleration, guest kernel), DevicePolicyManager (work profiles, fully-managed devices, COPE, enrollment), Android Automotive / TV / Wear (CarService, vehicle HAL, Leanback, TIF, Wear OS specifics), Print Services (PrintManager, IPP, PDF generation), or the Camera2 pipeline (Camera2 API, CaptureRequest/Result, camera HAL3). Chapters 59–62.

AOSP Part VI — Framework Core. Use when reasoning about system_server's boot sequence (the four boot phases, service registration, Watchdog), the Intent system (Intent matching, IntentFilter, IntentResolver, package visibility, intent verification), Activity & Window Management (ActivityTaskManagerService, WindowManagerService, activity lifecycle, task/stack model, splash screens), the window system (WindowState, SurfaceControl, input dispatching, focus, IME insets, transitions), the display system (DisplayManagerService, logical vs. physical displays, HDR, brightness, refresh-rate switching), or the View system (View hierarchy, measure/layout/draw, Canvas/RenderNode, hardware acceleration). Chapters 20–25.

AOSP Part VII — Framework Services. Use when reasoning about PackageManagerService (install/uninstall, APK parsing, permissions, package visibility), ContentProviders (ContentResolver, URI permissions, observers, FileProvider, MediaStore), Notifications (NMS, channels, ranker, posting/delivery, listener services, conversations, bubbles), Power Management (PowerManagerService, wake locks, Doze, App Standby, battery saver, BatteryStats), Background Tasks (JobScheduler, WorkManager, AlarmManager, foreground services, exact alarm policy), Multi-User (UserManagerService, profiles, restrictions, cross-user calls), Account & Sync (AccountManagerService, authenticator, syncadapter, SyncManager), Location (LocationManagerService, GPS/network/fused providers, GNSS HAL, geofencing), or Storage (vold, StorageManagerService, scoped storage, FUSE/sdcardfs, MediaProvider, SAF, FBE, adoptable storage, SQLite, SharedPreferences). Chapters 26–34.

AOSP Part I — Getting Started. Use when reasoning about the AOSP source tree at a high level, the repo/manifest workflow, the Soong (Android.bp) and Bazel/Kleaf build systems, lunch targets, the m build entry point, or aconfig feature flags (build-time vs. runtime, release configs, ramp/cleanup workflows). Chapters 1–3 (Introduction, Source Code & Build System, Feature Flags).

AOSP Part XIII — Infrastructure. Use when reasoning about Mainline modules / APEX (Project Mainline, APEX format/manifest/signing, apexd, module catalog, SDK Extensions, module boundaries), OTA updates (A/B updates, update_engine, payload format, Virtual A/B with snapshots, rollback protection), Virtualization (Android Virtualization Framework, pKVM, crosvm, microdroid), Testing (CTS/VTS/MTS, Tradefed, Ravenwood, atest, presubmit), or Debugging (Perfetto, atrace, simpleperf, heapprofd, logcat, dumpsys). Chapters 54–56.

AOSP Part II — Kernel & Boot. Use when reasoning about Android's bootloader handoff, init.rc / first-stage init / second-stage init, the Generic Kernel Image (GKI) and KMI stability, dm-verity / Android Verified Boot, the kernel's Android-specific subsystems (binder driver, ashmem→memfd, low-memory killer, PSI), vendor modules, or system properties (property_service, property contexts, ro/persist/sys/build prefixes). Chapters 4–6.

AOSP Part III — Native Foundation. Use when reasoning about Bionic (Android's libc/libm/libdl) and the dynamic linker, linker namespaces, GWP-ASan / MTE, memory management (jemalloc/scudo, ashmem/memfd, ION/dma-buf, lmkd, PSI), Binder IPC (transactions, parcels, one-copy semantics, AIDL/HIDL/NDK Binder, servicemanager, threadpool, death recipients), the HAL (Treble, HIDL→AIDL HAL migration, vendor/system split, hwservicemanager, VINTF), or the NDK (libandroid, JNI bindings, ABI compatibility). Chapters 7–11.

AOSP Part IV — Native Services & Media. Use when reasoning about surfaceflinger, audioserver, mediaserver, cameraserver, the graphics pipeline (BufferQueue, GraphicBuffer, OpenGL ES / Vulkan / Skia / HWUI, RenderThread, layer composition), the animation system (Choreographer, ValueAnimator, RenderNode animations, dynamic spring/fling), the audio stack (AudioFlinger, AudioPolicyManager, AAudio, OpenSL ES, Spatializer), the media pipeline (MediaCodec, MediaExtractor, NuPlayer, codec2 HAL), or the sensor stack (SensorService, sensor HAL, batching, wake-up sensors). Chapters 12–17.

AOSP Part XV — Practical. Use when reasoning about building a custom AOSP ROM end-to-end: picking a target device, syncing source, applying vendor blobs, branding, building, flashing the resulting images, and shipping OTA updates on your own channel. Chapter 65 (Custom ROM Guide).

AOSP Part V — Runtime. Use when reasoning about ART (dex2oat, AOT/JIT, baseline profiles, GC, oat/vdex/odex files, class loaders, JNI bridge) or the Native Bridge (Berberis, Houdini, cross-architecture native code execution, intercepting libc/JNI calls). Chapters 18–19.

AOSP Part IX — Security. Use when reasoning about SELinux on Android, Keystore/Keymint, Trusty TEE, gatekeeper/weaver, Android Verified Boot, dm-verity, hardware-backed attestation, Credential Manager (CredentialManagerService, credential providers, passkeys/FIDO2, password and autofill integration, digital credentials), or DRM (MediaDrm framework, Widevine L1/L2/L3, OEMCrypto, license acquisition, secure decoder/display path), or the LFI in-process sandbox (Lightweight Fault Isolation for untrusted code such as software codecs). Chapters 40–42, 68.

AOSP Part XI — System Apps. Use when reasoning about SystemUI (status bar, notification shade, keyguard, Quick Settings, Monet/dynamic color), Launcher3 (model loader, Recents/Overview, gesture nav, all-apps, predictions, work profile), or the Settings app (SettingsProvider, SettingsLib, search index, slice surface). Chapters 48–49.

AOSP Part X — UI Framework. Use when reasoning about Widgets and RemoteViews (AppWidget framework, RemoteViews, RemoteCompose, host/provider model), WebView (WebView Mainline module, Chromium content layer, renderer process, JS bridges, sandboxing), Accessibility (AccessibilityService, AccessibilityNodeInfo, TalkBack, magnification, Switch Access), or Internationalization (ICU, locale resolution, resource qualifier matching, RTL support, Unicode in AOSP). Chapters 44–46.

AOSP Part XII — AI & Devices. Use when reasoning about on-device ML in AOSP, NNAPI, the AppFunctions framework for assistant integration, the Computer Control flow, CompanionDeviceManager, or virtual devices (virtual displays/inputs/cameras for cross-device experiences), or the NpuManager module for on-device neural accelerators (model-load admission control, the NDK ANpuBuffer surface, the android.hardware.npu HAL). Chapters 51–53.

AOSP Internals — Appendices. Use when looking up a key file path (per-chapter table of the most important AOSP source files: build, init, kernel, HAL, framework services, system apps, infrastructure) or the meaning of an AOSP-specific acronym/term (Treble, VINTF, GKI, APEX, AIDL, HIDL, etc.), why Kotlin is absent from the public API, or what changed from Android 16 to Android 17. Reference material — load when you need a concrete path, a definition, or a changelog rather than narrative explanation.

AOSP Part VIII — Connectivity. Use when reasoning about Networking (ConnectivityService, Wi-Fi framework, netd, DNS resolver, VPN, tethering, NetworkSecurityConfig, VCN, Thread mesh), Telephony (TelephonyManager, PhoneInterfaceManager, RIL/RILD, modem AIDL, IMS framework, emergency calling), Bluetooth (Bluetooth Mainline module, BTA, GATT, A2DP/HFP/AVDTP, LE Audio, pairing, scanning, advertising), NFC (NfcAdapter/NfcService, NCI, tag dispatch, HCE, secure element, reader mode, NFC-F/V), or USB & ADB (USB gadget framework, host-mode USB, MTP/PTP, RNDIS tethering, adb daemon, adb over Wi-Fi). Chapters 35–39.

AOSP Part XIV — Device Support. Use when reasoning about per-architecture support (ARM 32/64, x86_64, RISC-V, ABI matrix, toolchains), the QEMU-based Android emulator (AVD format, hardware acceleration, guest kernel), DevicePolicyManager (work profiles, fully-managed devices, COPE, enrollment), Android Automotive / TV / Wear (CarService, vehicle HAL, Leanback, TIF, Wear OS specifics), Print Services (PrintManager, IPP, PDF generation), or the Camera2 pipeline (Camera2 API, CaptureRequest/Result, camera HAL3). Chapters 59–62.

AOSP Part VI — Framework Core. Use when reasoning about system_server's boot sequence (the four boot phases, service registration, Watchdog), the Intent system (Intent matching, IntentFilter, IntentResolver, package visibility, intent verification), Activity & Window Management (ActivityTaskManagerService, WindowManagerService, activity lifecycle, task/stack model, splash screens), the window system (WindowState, SurfaceControl, input dispatching, focus, IME insets, transitions), the display system (DisplayManagerService, logical vs. physical displays, HDR, brightness, refresh-rate switching), or the View system (View hierarchy, measure/layout/draw, Canvas/RenderNode, hardware acceleration). Chapters 20–25.

AOSP Part VII — Framework Services. Use when reasoning about PackageManagerService (install/uninstall, APK parsing, permissions, package visibility), ContentProviders (ContentResolver, URI permissions, observers, FileProvider, MediaStore), Notifications (NMS, channels, ranker, posting/delivery, listener services, conversations, bubbles), Power Management (PowerManagerService, wake locks, Doze, App Standby, battery saver, BatteryStats), Background Tasks (JobScheduler, WorkManager, AlarmManager, foreground services, exact alarm policy), Multi-User (UserManagerService, profiles, restrictions, cross-user calls), Account & Sync (AccountManagerService, authenticator, syncadapter, SyncManager), Location (LocationManagerService, GPS/network/fused providers, GNSS HAL, geofencing), or Storage (vold, StorageManagerService, scoped storage, FUSE/sdcardfs, MediaProvider, SAF, FBE, adoptable storage, SQLite, SharedPreferences). Chapters 26–34.

AOSP Part I — Getting Started. Use when reasoning about the AOSP source tree at a high level, the repo/manifest workflow, the Soong (Android.bp) and Bazel/Kleaf build systems, lunch targets, the m build entry point, or aconfig feature flags (build-time vs. runtime, release configs, ramp/cleanup workflows). Chapters 1–3 (Introduction, Source Code & Build System, Feature Flags).

AOSP Part XIII — Infrastructure. Use when reasoning about Mainline modules / APEX (Project Mainline, APEX format/manifest/signing, apexd, module catalog, SDK Extensions, module boundaries), OTA updates (A/B updates, update_engine, payload format, Virtual A/B with snapshots, rollback protection), Virtualization (Android Virtualization Framework, pKVM, crosvm, microdroid), Testing (CTS/VTS/MTS, Tradefed, Ravenwood, atest, presubmit), or Debugging (Perfetto, atrace, simpleperf, heapprofd, logcat, dumpsys). Chapters 54–56.

AOSP Part II — Kernel & Boot. Use when reasoning about Android's bootloader handoff, init.rc / first-stage init / second-stage init, the Generic Kernel Image (GKI) and KMI stability, dm-verity / Android Verified Boot, the kernel's Android-specific subsystems (binder driver, ashmem→memfd, low-memory killer, PSI), vendor modules, or system properties (property_service, property contexts, ro/persist/sys/build prefixes). Chapters 4–6.

AOSP Part III — Native Foundation. Use when reasoning about Bionic (Android's libc/libm/libdl) and the dynamic linker, linker namespaces, GWP-ASan / MTE, memory management (jemalloc/scudo, ashmem/memfd, ION/dma-buf, lmkd, PSI), Binder IPC (transactions, parcels, one-copy semantics, AIDL/HIDL/NDK Binder, servicemanager, threadpool, death recipients), the HAL (Treble, HIDL→AIDL HAL migration, vendor/system split, hwservicemanager, VINTF), or the NDK (libandroid, JNI bindings, ABI compatibility). Chapters 7–11.

AOSP Part IV — Native Services & Media. Use when reasoning about surfaceflinger, audioserver, mediaserver, cameraserver, the graphics pipeline (BufferQueue, GraphicBuffer, OpenGL ES / Vulkan / Skia / HWUI, RenderThread, layer composition), the animation system (Choreographer, ValueAnimator, RenderNode animations, dynamic spring/fling), the audio stack (AudioFlinger, AudioPolicyManager, AAudio, OpenSL ES, Spatializer), the media pipeline (MediaCodec, MediaExtractor, NuPlayer, codec2 HAL), or the sensor stack (SensorService, sensor HAL, batching, wake-up sensors). Chapters 12–17.

AOSP Part XV — Practical. Use when reasoning about building a custom AOSP ROM end-to-end: picking a target device, syncing source, applying vendor blobs, branding, building, flashing the resulting images, and shipping OTA updates on your own channel. Chapter 65 (Custom ROM Guide).

AOSP Part V — Runtime. Use when reasoning about ART (dex2oat, AOT/JIT, baseline profiles, GC, oat/vdex/odex files, class loaders, JNI bridge) or the Native Bridge (Berberis, Houdini, cross-architecture native code execution, intercepting libc/JNI calls). Chapters 18–19.

AOSP Part IX — Security. Use when reasoning about SELinux on Android, Keystore/Keymint, Trusty TEE, gatekeeper/weaver, Android Verified Boot, dm-verity, hardware-backed attestation, Credential Manager (CredentialManagerService, credential providers, passkeys/FIDO2, password and autofill integration, digital credentials), or DRM (MediaDrm framework, Widevine L1/L2/L3, OEMCrypto, license acquisition, secure decoder/display path), or the LFI in-process sandbox (Lightweight Fault Isolation for untrusted code such as software codecs). Chapters 40–42, 68.

AOSP Part XI — System Apps. Use when reasoning about SystemUI (status bar, notification shade, keyguard, Quick Settings, Monet/dynamic color), Launcher3 (model loader, Recents/Overview, gesture nav, all-apps, predictions, work profile), or the Settings app (SettingsProvider, SettingsLib, search index, slice surface). Chapters 48–49.

AOSP Part X — UI Framework. Use when reasoning about Widgets and RemoteViews (AppWidget framework, RemoteViews, RemoteCompose, host/provider model), WebView (WebView Mainline module, Chromium content layer, renderer process, JS bridges, sandboxing), Accessibility (AccessibilityService, AccessibilityNodeInfo, TalkBack, magnification, Switch Access), or Internationalization (ICU, locale resolution, resource qualifier matching, RTL support, Unicode in AOSP). Chapters 44–46.

Update or polish the AOSP Internals reference book (the chapters at the repo root -- NN-slug.md -- plus the appendices and the generated agents/ Part-skills) so it is accurate and current for a newly-synced or newer AOSP/Android source tree. Use this whenever the user says anything like "polish the book for Android NN", "update the reference book to the new AOSP version", "the AOSP source got re-synced, bring the book up to date", "deep-rewrite the chapters against the new source", or -- importantly -- "cover the new Android modules/projects in the book". It drives a resumable, changeset-prioritized, per-chapter convergent deep-rewrite with an agent-team accuracy + Mermaid review loop, and MANDATORILY runs a gap analysis that finds newly-added modules/projects and folds them into existing chapters (or adds new chapters/Parts only by an explicit threshold). Trigger it even when the user only says "update the book for the new Android" without naming this process, and even when they only want the new-modules par

Compare two AOSP releases (e.g. android-16 vs android-17) and turn the diff into a written report of the important platform changes. Use this whenever the user wants to know what changed between two Android/AOSP versions, generate an "Android N updates" report or appendix, diff two repo manifests/branches, find newly-added projects or new code modules in a version, or fill gaps in an existing version-changes report. Triggers on requests like "what's new in android 17", "diff android16 to android17", "find modules added in the new release that my report is missing", or "compare two AOSP branches with commit history". Reuses the repo's tools/manifest_snapshot.py rather than reinventing the diff, and uses an agent team to source-verify and append missing modules.

Patterns for writing technical book chapters in Markdown with Mermaid diagrams, served via MkDocs. Use this skill whenever writing, editing, reviewing, adding, removing, or renaming book chapters, organizing multi-chapter content, fixing Mermaid rendering issues, or changing the book's structure. Also triggers when updating mkdocs.yml, docs/ symlinks, or navigation — even if the user just says "add a chapter" or "reorganize sections" without mentioning MkDocs.