Android Development

Agenda System Linux Bionic libc Dalvik SDK Project Compilation Tools Première partie: Le développement Android natif

System Linux Bionic libc Dalvik Base on 2.6 New Lock type: Wakelock (suspend blocker accessible at userspace level) Hooks for the Android security model → Fork A task force is working on contributing back to the Linux kernel, but it's not a priority for Google. Bionic libc License: keep GPL out of userspace → BSD Size: ~200k, loaded in each process Speed Native code compiled against bionic and not glibc Dalvik Open source: http://code.google.com/p/dalvik/ Executes DEX bytecode Register based instead of stack based in Java VM Première partie: Le développement Android natif

SDK Project Compilation Tools Eclipse (ADT plugin) Android command, Ant Compilation Compile to Java bytecode Convert Java bytecode to DEX with dx tool Tools DDMS (Dalvik Debug Monitor Server) ADB (Android Debug Bridge): logcat, shell, push/pull AAPT, DEXDUMP (used by other tools to create APK) - ADT : Android Developper Tools - Inclus les tools du SDK dans Eclipse - Facilite la création de projet, l'export d'APK signé, permet de visualiser les GUI XML, ... --------- - ADB : Android Debug Bridge - Logcat - Shell - Push/pull - DDMS: Davlik Debug Monitor Server - Voir les Threads/Process - Voir l'utilisation du Java Heap - Dump du Java Heap - Suivre les allocations des objects Java - Parcourir les fichiers - Capture d'écran - Controler l'émulateur (GPS, appel, sms, ..) -------- AAPT: Android Asset Packaging Tool, resources de/compiler (androidmanifest.xml, image) DEXDUMP: get information about dex file

APK Classes.dex (Compiled classes) Resources (strings, layouts, images, ..) Raw files (native binaries, librairies) META.INF (files signatures) Resources.arsc (resources table) XML Manifest (permissions, ...) Première partie: Le développement Android natif

DEX Structure Decompiling header, strings ids, type, ids, proto ids, field ids, method ids, class defs, data, link data Decompiling bak/smali http://code.google.com/p/smali/ dex2jar http://code.google.com/p/dex2jar/ Repackage Apktool http://code.google.com/p/android-apktool/

Links Première partie: Le développement Android natif http://www.kroah.com/log/linux/android-kernel-problems.html http://lwn.net/Articles/416690/ http://www.dalvikvm.com/ DEX format http://source.android.com/tech/dalvik/dex-format.html http://strazzere.com/blog/?tag=dex http://www.retrodev.com/android/dexformat.html (outdated) Première partie: Le développement Android natif