Debug Android native code

Introduction

     How to debug native code running on emulator/devices?    There are  some tools both in AOSP and system.image that can be used to achieve the aim.

• device side:   /system/bin/gdbserver
• AOSP side :   NDK,   prebuild/linux-x86/toolchain/arm-eabi-4.4.0/bin/arm-eabi-gdb   

    The baisc idea is using adb to route gdb command between  x86 and android device, below is a rude demonstration:

 

How to using GDB debugging android

step1: use adb shell ps to list process list,  and select which process want to debug, for example android.com.media whose pid=668

# adb shell ps

step2:  run gdbserver with a given tcp port,  for example port 10000

# adb shell gdbserver :10000 --attach 668

Attached; pid=quit

Listening on port 10000

step3: run adb to forward port 10000 to target devices

# adb forward tcp:5039 tcp:10000     //replace 5039 with the real listen port of adb server

step4: run gdb in NDK

# prebuild/linux-x86/toolchain/arm-eabi-4.4.0/bin/arm-eabi-gdb

step5:  connect gdb to gdbserver,   run gdb command 

(gdb) target remote localhost:5039