Debugging Native Code for android

from:http://the-b.org/Android 

Debugging Native Code

If you're working on the framework, you're in luck. Debugging native code is pretty easy. Here is how to do it for the emulator. For actual devices, you can forgo the port forwarding and substitute something else in for generic.

I'm assuming you're debugging a Java application which calls out to a native library here. You can also replace app_process with system_server or any other binary.

1. cd ~/mydroid
2. lunch (select your target here: generic-eng)
3. telnet localhost 5554
   1. In telnet, type: redir add tcp:10000:10000
   2. Press CTRL-] and, at the telnet> prompt, type: quit
4. In another window: adb shell gdbserver 10.0.2.15:10000 --attach <PID of program>
5. arm-eabi-gdb out/target/product/generic/symbols/system/bin/app_process
6. In gdb, type: set solib-search-path out/target/product/generic/symbols/system/lib:out/target/product/generic/symbols/system/bin
7. In gdb, type: target remote localhost:10000