Build GDB for Android

0. introduction

If you need GDB on Android, it's very likely that you got a copy without some feature like gcore. So a good idea is to build GDB on your own to acquire these features.

Following process is done on Fedora 21 and should be compatible with other linux platform.

1. gdb part

source: https://android.googlesource.com/toolchain/gdb.git

Here we build version 7.7

Install termcap and bison, or there will be error during make process.

In file /gdb-7.7/gdb/remote.c, search for "packet reply is too long" and modify as follows:

//if(buf_len > 2 * rsa->sizeof_g_packet)
//    error(_("Remote 'g' packet reply is too long: %s"),rs->buf);

if(buf_len > 2 * rsa->sizeof_g_packet)
{
    rsa->sizeof_g_packet = buf_len;
...

Then run the following command:

./configure --target=arm-linux-androideabi --prefix=<result_absolute_path>
sudo make
sudo make install

If you see "no termcap library found", install termcap.

If you see something like "multiple definition of main" or "undefined reference to 'c_parse'", install bison.

2. gdbserver part

First, download android ndk and run:

chmod a+x android-ndk-r10c-darwin-x86_64.bin
./android-ndk-r10c-darwin-x86_64.bin

and in the extracted file directory, run:

sudo ./build/tools/make-standalone-toolchain.sh --system=linux-x86_64 --toolchain=arm-linux-androideabi-4.9 --install-dir=<target_dir> --ndk-dir=<extracted_file_dir>

This will install android toolchain to . Then add <target_dir>/bin to PATH.

In path ./gdb-7.7/gdb/gdbserver, do as follows:

CC=arm-linux-androideabi-gcc ./configure --target=arm-linux-androideabi --host=arm-linux-androideabi --prefix=<result_absolute_path>
sudo make && sudo makeinstal

If there is error "arm-linux-androideabi-gcc: command not found", replace "CC=arm-linux-androideabi-gcc" with "CC=<gccabsolutepath>".

3. done

Now two files are available: arm-linux-androideabi-gdb and gdbserver. Strip command is helpful if you need a smaller version.

We can push gdbserver to android and run:

./gdbserver :<port_id> --attach=<pid>

Then run in the host:

adb forward tcp:<port_id> tcp:<port_id>
./arm-linux-androideabi-gdb
target remote :<port_id>

You can download the two files here: gdbserver, arm-linux-androideabi-gdb.