ROM Cooking - Droidcon UK 20013

Slides of the Droidcon UK 2013 Workshop made by Sylvain Galand from Genymobile about ROM Cooking.

Transcript

1. ROM COOKING
2. AGENDA 01 Android 02 Architecture 03 Hardware Support 04 AOSP 05 Build Demo: Add a kernel module Android style
3. ANDROID STORY … in a nutshell
4. 2003 Android Inc. 2005 Google 2008 1st gPhone ! ANDROID STORY History
5. ANDROID STORY Initial target
6. ANDROID STORY Multiple targets
7. ANDROID STORY and more...
8. ANDROID STORY Releases 1.5 3.x 1.6 2.x April 30, 2009 September 15, 2009 October 2009 May 2010 December 2010 Febuary 2011 FAST & CURIOUS 4.x October 2011 July 2012 November 2012 July 2013 ... ...
9. ANDROID STORY Figures 1 M Apps 75 % market share 900 M Devices 50G dls ! Smartphones IDC 2013 1.5M/day
10. :’( TRADEMARK Android is a ANDROID STORY Android is my name
11. ANDROID STORY Android Compliancy Compatibility Test Suite Compatibility Definition Document CDD Let Google test it when you already did everything Compatibility Test Suite manual testing CTS CTS man. Big G.
12. but it’s open source NOT an OPEN SOURCE PROJECT Android is ANDROID STORY Android, an open source project ?
13. is the GOOGLE ANDROID STORY Open Handset Aliance
14. ANDROID ARCHITECTURE underneath Android !
15. Sensors Camera Bluetooth GSM, 3G, 4G, LTE GPS Touchscreen ANDROID DEVICE ANDROID ARCHITECTURE So much features
16. as ANDROID kernel LINUX ANDROID ARCHITECTURE Mon coeur
17. ANDROID ARCHITECTURE The big picture
18. ANDROID ARCHITECTURE The big picture
19. IPC BINDER POWER MANAGEMENT WAKELOCK MORE TIMER, OOM, LOGGER ... ANDROID ARCHITECTURE Linux modifications
20. ANDROID HARDWARE SUPPORT Closed as hell !
21. GPL for the kernel ! Apache Framework & Apps ANDROID HARDWARE SUPPORT Open source licensing
22. ANDROID HARDWARE SUPPORT Hardware Abstraction Layer 9000
23. ANDROID HARDWARE SUPPORT Camera
24. DRIVERS ARE CLOSED SOURCE DRIVERS ARE NOT AVAILABLE DRIVERS ARE F**ING ESSENTIALS ! ANDROID HARDWARE SUPPORT U.S. Route 66
25. ANDROID OPEN SOURCE PROJECT Use the source, Luke.
26. Google made a tool called “repo” ! ANDROID OPEN SOURCE PROJECT repo Everything is available through git repositories.
27. Branch switching is risky in my opinion ANDROID OPEN SOURCE PROJECT Tree of life repo init -u https://android.googlesource.com/platform/manifest -b android-4.3.1_r1
28. This will take hours (if it didn’t fail), enjoy. ANDROID OPEN SOURCE PROJECT Sync repo sync
29. ANDROID OPEN SOURCE PROJECT Folders 1/4 Google Android libc implementation Bootloader & recovery Build system Compatibility Test Suite bionic/ bootable/ build/ cts/
30. ANDROID OPEN SOURCE PROJECT Folders 2/4 Dev tools, debug applications... Configuration for each target device External libraries Android framework develope ment/ device/ external/ framework/
31. ANDROID OPEN SOURCE PROJECT Folders 3/4 Java implementation (Apache Harmony) Native Development Kit Results of your build Android base applications (sms, camera…) libcore/ ndk/ out/ packages/
32. ANDROID OPEN SOURCE PROJECT Folders 4/4 Binaries (toolchain, gdbserver…) Software developement kit Base : init, toolbox, logcat... Vendor directory (libs, apps) prebuilt/ sdk/ system/ vendor/
33. BUILD ANDROID make -j42
34. « the definition of open: mkdir android cd android repo init repo sync make » ANDY RUBIN Android’s dad BUILD ANDROID What a classy first tweet !
35. that simple NOT REALLY Sorry Andy but it’s BUILD ANDROID make : command not found
36. Ubuntu 10.04 for builds BUILD ANDROID sources.android.com a LOT of dependencies must be installed you can chroot it !
37. BUILD ANDROID prepare the environment #source build/envsetup.sh including device/samsung/maguro/vendorsetup.sh including device/samsung/tuna/vendorsetup.sh including device/ti/panda/vendorsetup.sh including sdk/bash_completion/adb.bash Example : device/samsung/maguro/vendorsetup.sh add_lunch_combo full_maguro-userdebug
38. BUILD ANDROID Lunch time #lunch You're building on Linux Lunch menu... pick a combo: 1. full-eng 2. full_x86-eng 3. vbox_x86-eng 4. full_maguro-userdebug 5. full_tuna-userdebug 6. full_panda-eng Which would you like? [full-eng]
39. BUILD ANDROID sources.android.com # make –j18
40. on your phone WON’T BOOT This build BUILD ANDROID #FAIL
41. BUILD ANDROID https://developers.google.com/android/nexus/drivers
42. Congratulations ! COOKING YOUR OWN ROM You are now proud owners of the skill : BUILD ANDROID #WIN
43. YOU BUILD 100% AOSP EXPERIENCE YOU CAN MODIFY EVERYTHING YOU CAN ADD ANYTHING BUILD ANDROID Start coding !
44. KERNEL MODULE The Android way !
45. MIX ANDROID KERNEL Dance with the *
46. MIX ANDROID KERNEL init dev # in init.rc on boot insmod /system/lib/modules/droidcon.ko chown system system /dev/droidcon chmod 0600 /dev/droidcon # in ./device/<vendor>/<product>/device.mk PRODUCT_COPY_FILES := \ device/<vendor>/<product>/droidcon.ko: system/lib/modules/droidcon.ko
47. MIX ANDROID KERNEL /dev/droidcon test adb shell # ls -l /dev/droidcon crw------- system system 249, 0 droidcon # echo Hello > /dev/droidcon # cat /dev/droidcon hELLO #
48. MIX ANDROID KERNEL Dance with the *
49. MIX ANDROID KERNEL hardware/droidcon/lib # in libdroidcon.h ssize_t droidcon_getdata(void *buf, size_t count); ssize_t droidcon_putdata(const void *buf, size_t count); void droidcon_clear(void); # This is the (often closed) part where we should do all the complicated code
50. MIX ANDROID KERNEL Dance with the *
51. MIX ANDROID KERNEL frameworks/base/core/java/android/droidcon/ #LibDroidcon.java package android.droidcon; public class LibDroidcon { public native static void clear(); public native static String getData() throws DroidconException; public native static void putData(String in) throws DroidconException; static { System.loadLibrary("droidcon_jni"); } }
52. MIX ANDROID KERNEL hardware/droidcon/jni/ #android_droidcon_LibDroidcon.c JNIEXPORT void JNICALL Java_android_droidcon_LibDroidcon_putData(JNIEnv *env, jclass cls, jstring string) { int ret; const char *buff = (*env)->GetStringUTFChars(env, string, NULL); int length = (*env)->GetStringLength(env, string); ret = droidcon_putdata(buff, length); if (ret < 0) { ThrowDroidconException(env, "fail to put data"); } (*env)->ReleaseStringUTFChars(env, string, buff); }
53. MIX ANDROID KERNEL Dance with the *
54. MIX ANDROID KERNEL framework/base/droidcon/java/android/droidcon/ #IDroidconManager.aidl package android.droidcon; /** {@hide} */ interface IDroidconManager { void clear(); String getData(); void putData(String data); }
55. MIX ANDROID KERNEL frameworks/base/services/java/com/android/server/ #DroidconService.java class DroidconService extends IDroidconManager.Stub { public String getData() { enforceAccessPermission(); try { return LibDroidcon.getData(); } catch(DroidconException e) { Slog.d(TAG, "cannot getdata"); } return null; } ... private void enforceAccessPermission() { … } }
56. MIX ANDROID KERNEL Hacking SystemServer.java #SystemServer.java ... public void run() { ... try { Slog.i(TAG, "Droidcon Service"); droidconService = new DroidconService(context); ServiceManager.addService(Context.DROIDCON_SERVICE, droidconService); } catch (Throwable e) { reportWtf("starting Droidcon Service", e); } ...
57. MIX ANDROID KERNEL Dance with the *
58. MIX ANDROID KERNEL framework/base/droidcon/java/android/droidcon # DroidconManager.java public class DroidconManager { IDroidconManager mService; public DroidconManager(IDroidconManager service) { mService = service; } public String getData() { try { return mService.getData(); } catch (RemoteException e) { e.printStackTrace(); } return null; } }
59. MIX ANDROID KERNEL Hacking ContextImpl.java # DroidconManager.java class ContextImpl extends Context { static { ... registerService(DROIDCON_SERVICE, new ServiceFetcher() { public Object createService(ContextImpl ctx){ IBinder b = ServiceManager .getService (DROIDCON_SERVICE); IDroidconManager service = IDroidconManager.Stub.asInterface(b); return new DroidconManager(service); }}); } ...
60. and configure our IDE BUILD OUR SDK We can now MIX ANDROID KERNEL make update-api ; make sdk
61. MIX ANDROID KERNEL Code an awesome app ! DroidconManager droidconManager; droidconManager = (DroidconManager) this.getSystemService(DROIDCON_SERVICE); droidconManager.putData(“Hello Droidcon London!”);
62. MIX ANDROID KERNEL TADAM !
63. Thank You for your time ! Now let’s finish this hackathon ! Build your own ROM Use the Sources Buy devices with AOSP support SYLVAIN GALAND @sylvaingaland http://slvn.fr/+ sgaland@genymobile.com Thanks Cédric Cabessa for the awesome open source droidcon device !