Android internals 03 - Build system, emulator (rev_1.1)
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The document discusses Android internals and provides an overview of the Android build system and emulator. It describes how the build system is based on GNU Make and uses Android.mk and Makefile files. It also summarizes the emulator and how it allows running the full Android stack using Qemu virtualization. Key targets and tools for building, debugging, and managing emulators are also highlighted.
Android internals 03 - Build system, emulator (rev_1.1)
- 1. Android internals Egor Elizarov SPbSU 2012
- 2. Legal info Android internals by Egor Elizarov is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License You are free to – copy, distribute, display, and perform the work – make derivative works Under the following conditions – Attribution. You must give the original author credit – Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one All pictures and trademarks are the property of their respective owners. Use of these trademarks and pictures is subject to owners permissions. Corrections, suggestions, contributions and translations are welcome! 2 Egor Elizarov SPbSU 2012
- 3. Lecture 3 Android build system, Emulator yegor.yelizarov(at)gmail.com Rev: 1.1 Last update: 05/30/2012 http://vk.com/android_internals 3 Egor Elizarov SPbSU 2012
- 4. Previous time AOSP High level architecture Android OS bring up CTS & CDD repo / git / gerrit Code layout 4 Egor Elizarov SPbSU 2012
- 5. Android build system Based on GNU Make Build system code is in “build” directory (./build/core/main.mk - start point) Android.mk files All output and temporary files are in “out” directory 5 Egor Elizarov SPbSU 2012
- 6. Makefile structure Structure: Target: depenencies List of commands Usage: make target 6 Egor Elizarov SPbSU 2012
- 7. Interesting files Android.mk — build scenario for module buildspec.mk — variable defenitions for build system envsetup.sh — setup environment, add some helper functions 7 Egor Elizarov SPbSU 2012
- 8. Sample Android.mk LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_SRC_FILES := list_of_sources LOCAL_C_INCLUDES := list_of_directories_with_header_files LOCAL_SHARED_LIBRARIES := list_of_shared_libraries LOCAL_STATIC_LABRARIES := list_of_static_libraries LOCAL_MODULE_TAGS := debug LOCAL_MODULE := module_name include $(BUILD_EXECUTABLE) 8 Egor Elizarov SPbSU 2012
- 9. More variables LOCAL_MODULE_PATH := install_path LOCAL_CFLAGS := flags_for_compiler LOCAL_LDFLAGS := flags_for_linker LOCAL_OVERRIDES_PACKAGES := packages_to_be_dropped Etc. 9 Egor Elizarov SPbSU 2012
- 10. Target hierarchy CPU type Bare schematics Fixed peripherals Fixed applications 10 Egor Elizarov SPbSU 2012
- 11. buildspec.mk TARGER_PRODUCT = product_name TARGET_BUILD_TYPE = debug SHOW_COMMANDS = true USE_CCACHE = 1 BUILD_TINY_ANDROID = true (board bring up/ low level debugging) 11 Egor Elizarov SPbSU 2012
- 12. Some make targets make droid (default target) make update-api (update current API) make sdk (build SDK) make help (prints more targets) 12 Egor Elizarov SPbSU 2012
- 13. Build process 13 Egor Elizarov SPbSU 2012
- 14. Building AOSP cd AOSP . build/envsetup.sh lunch Select generic-eng version make -j4 14 Egor Elizarov SPbSU 2012
- 15. Add new program 15 Egor Elizarov SPbSU 2012
- 16. Board specific files BoardConfig.mk (Target configuration) Board_name.mk (board related defenitions, list of packages) Device.mk (list of files to be copied, list of packages, etc.) 16 Egor Elizarov SPbSU 2012
- 17. Android emulator Based on Qemu VM Goldfish – codename for emulator Code in development/tools/emulator & external/qemu Provided as part of SDK 17 Egor Elizarov SPbSU 2012
- 18. Emulator features Runs full Android stack down to the kernel level ARM v5 CPU and correcponding MMU LCD with different resolutions GSM modem Simulates application interrupts, data channel lost, etc. 18 Egor Elizarov SPbSU 2012
- 19. Qemu Single loop for each core Worker threads for long term tasks Tiny Code Generator (TCG) Kernel Virtual Machine (KVM) 19 Egor Elizarov SPbSU 2012
- 20. Emulator window 20 Egor Elizarov SPbSU 2012
- 21. Tools android — control AVD, update SDK, manage android projects emulator — launches emulator adb — remote debug console mksdcard — create SD card image 21 Egor Elizarov SPbSU 2012
- 22. Android Debug Bridge adb kill-server adb devices adb logcat adb shell adb push what where adb pull what where 22 Egor Elizarov SPbSU 2012
- 23. ADB internals USB or TCP/IP 23 Egor Elizarov SPbSU 2012
- 24. Launch emulator $ out/host/linux-x86/bin/emulator & $ adb kill-server $ adb shell 24 Egor Elizarov SPbSU 2012
- 25. Target filesystem layout /system — main system directory /data — main data directory /cache — Dalvik cache /sdcard — SD card mount point /etc; /sys; /proc; /dev; /sbin; /root; /mnt — derived from linux 25 Egor Elizarov SPbSU 2012
- 26. Next time “Androdized” kernel Bionic standard C library Logging system Source: http://androidcommunity.com 26 Egor Elizarov SPbSU 2012
- 27. Useful links http://vk.com/android_internals http://mrbook.org/tutorials/make/ http://elinux.org/Android_Build_System K. Yaghmour. Embedded Android. Early Release, O'Reilly, October 2011 http://developer.android.com/guide/developing/tools/emulator.html http://developer.android.com/guide/developing/devices/emulator.html http://blog.vmsplice.net/2011/03/qemu-internals-overall-architecture-and.html 27 Egor Elizarov SPbSU 2012
- 28. Thanks to Sergey Matyukevich for review and advices (www.linkedin.com/pub/sergey- matyukevich/31/889/769) Nikolay F. Fominykh for review and advices Nikita Shulga for advices and notes (http://www.linkedin.com/pub/nikita- shulga/8/582/287) 28 Egor Elizarov SPbSU 2012