远程调试步骤
在Android设备上启动gdbserver并attach你想调试的进程，并指定监听调试命令的端口（此端口是TV上的端口)
$ adb shell
# ps |grep media #查看要调试进程的PID,以mediaserver进程为例
# gdbserver :1234 --attach 96 #:1234是端口号，96 是进程ID
如果设备上没有gdbserver,可以由google ndk中获取，在ndk的如下目录可以找到这个文件：
android-ndk-r8/toolchains/arm-linux-androideabi-4.9/prebuilt/android-arm
可以将此文件先推送到设备上。
进入源码服务器，比如5520编译服务器地址10.9.44.42
进入到源码工程目录下，进行环境配置，执行build文件夹下的envsetup.sh和choosecombo xx xx xx 命令，这时就可以使用gdbclient了。
adb connect 电视，成功后执行端口映射，将pc机的1234端口映射到电视1234端口
$ adb forward tcp:1234 tcp:1234 #端口映射，将pc机的1234端口映射到电视的1234端口
$ 在pc端的源码根目录下，执行 gdbclient -e mediaserver -p 1234 #从1234端口调试mediaserver
$ target remote:1234
接下来通过file命令来加载将要调试的可执行文件，对于android application来说，均为 out/target/product/generic/symbols/system/bin/app_process 这个文件，及设置搜索solib的搜索路径。
$file /home/luckychou/share/workspace/MT5520_DEV_Q3/release/android/l-pdk/out/target/product/mt5520_ll/symbols/system/bin/app_process32
$ set solib-search-path /home/luckychou/share/workspace/MT5520_DEV_Q3/release/android/l-pdk/out/target/product/mt5520_ll/symbols/system/lib
$ set solib-absolute-prefix /home/luckychou/share/workspace/MT5520_DEV_Q3/release/android/l-pdk/out/target/product/mt5520_ll/symbols/system/lib
之后，即可如调试PC端的C/C++ code一样，下断点，执行，查看内存内容，查看back trace等，来进行对library的debug工作：
If the program you’re backtracing is multi-threaded, you might want to get a backtrace for all threads:
(gdb) thread apply all bt
Another thing which is quite helpful to report is what variables were set locally at each point in the stack:
(gdb) bt full
You might want to report the output of the combination of the preceding options:
(gdb) thread apply all bt full
And if this is too much irrelevant output, you might want to keep only a few calls, such as the top 10:
(gdb) thread apply all bt full 10
If you have a large backtrace, you can log gdb output to a file (the default is gdb.txt):
(gdb) set logging on
(gdb) set logging file myfile.txt
还有很多其他gdb有用的命令，可以参考下网上的。