Mobile/Fennec/Android/GDB

Note: the names JimDB and moz-gdb seem to be used interchangeably, meaning the same thing.

Using JimDB (Or, Android GDB with Niceness)

Prebuilt binaries

Linux

Download page

Run 'git pull' inside the utils directory to get the latest GDB utilities.

GDB utilities

A set of tools to make Fennec development on Android easier.

Source and documentation.

Building moz-gdb

There are two things to build here: the gdb you'll run on your computer, and the gdbserver you'll install on the device. JimDB's gdb takes care of automatically running /data/local/gdbserver on the device, once it's correctly installed.

Building gdb

Linux

Get required packages:

sudo apt-get install bison flex libncurses5-dev texinfo python2.7-dev

Get source:

git clone git://github.com/darchons/android-gdb.git
cd android-gdb
git checkout android-gdb_7_3

Run configure and make:

mkdir android-gdb-objdir
cd android-gdb-objdir
export prefix=/nonexistent
/path/to/android-gdb/configure --target=arm-elf-linux --with-python=yes --prefix=$prefix \
  --with-gdb-datadir=$prefix/utils --with-system-gdbinit=$prefix/utils/gdbinit
make -j4

Reminder: Don't use ~ in the paths you pass here, as Bash wouldn't evaluate it!

The gdb binary will be located at android-gdb-objdir/gdb/gdb

Mac OS X

NOTE (BenWa): It failed to built with clang on 2012/01/09

Get required packages:

port install bison flex ncurses texinfo python27

Get source:

git clone git://github.com/darchons/android-gdb.git
cd android-gdb
git checkout android-gdb_7_3

Run configure and make:

mkdir android-gdb-objdir
cd android-gdb-objdir
export prefix=/nonexistent
/path/to/android-gdb/configure --target=arm-elf-linux --enable-targets=all --with-python=yes --prefix=$prefix \
  --with-gdb-datadir=$prefix/utils --with-system-gdbinit=$prefix/utils/gdbinit
make -j4

Reminder: Don't use ~ in the paths you pass here, as Bash wouldn't evaluate it!

The gdb binary will be located at android-gdb-objdir/gdb/gdb

Building gdbserver

Linux

Create an NDK toolchain:

cd /PATH/TO/NDK
./build/tools/make-standalone-toolchain.sh

This will tell you that the toolchain was packaged somewhere like /tmp/ndk-username/arm-linux-androideabi-4.4.3.tar.bz2

Extract that toolchain somewhere:

mkdir ~/android-toolchain
cd ~/android-toolchain
tar -xvf /tmp/ndk-username/arm-linux-androideabi-4.4.3.tar.bz2

Make sure NDK toolchain is in PATH:

export PATH=~/android-toolchain/arm-linux-androideabi-4.4.3/bin:$PATH

Run configure and make for gdbserver:

mkdir android-gdbserver-objdir
cd android-gdbserver-objdir
/path/to/android-gdb/gdb/gdbserver/configure --host=arm-linux-androideabi \
  --with-sysroot=/PATH/TO/NDK/platforms/android-9/arch-arm
make -j4

The gdbserver binary will be located at android-gdbserver-objdir/gdbserver.

Reminder: Don't use ~ in the paths you pass here, as Bash wouldn't evaluate it!

Install it on your device:

adb push gdbserver /data/local

Mac OS X

Setup a toolchain environment for your build:

/PATH/TO/NDK/build/tools/make-standalone-toolchain.sh --install-dir=android-9-toolchain --platform=android-9

Run configure and make for gdbserver:

mkdir android-gdbserver-objdir
cd android-gdbserver-objdir
export PATH=android-9-toolchain/bin:$PATH
../android-gdb/gdb/gdbserver/configure --host=arm-linux-androideabi
make -j4

The gdbserver binary will be located at android-gdbserver-objdir/gdbserver.

Install it on your device:

adb push gdbserver /data/local

Set up the moz-gdb directory

Once you've built JimDB, you need to create and populate a moz-gdb directory as explained below.

Indeed, GDB utilities assume the following moz-gdb directory structure:

./bin/
    gdb
    gdbserver
./utils/
    gdbinit
    python/

Execute the following commands to create and set up the moz-gdb directory:

mkdir -p moz-gdb/bin
cp android-gdb-objdir/gdb/gdb moz-gdb/bin
cp android-gdbserver-objdir/gdbserver moz-gdb/bin
git clone git://github.com/darchons/android-gdbutils.git moz-gdb/utils

Now edit this file:

moz-gdb/utils/gdbinit

and uncomment (remove the #'s) and set the following variables:

 python feninit.default.objdir      # set it to your fennec object directory
 python feninit.default.srcroot     # set it to your source directory

Linux

Make sure your paths are absolute! The gdbinit file, even though it specifies relative paths by default, will not correctly load debug symbols unless you specify absolute paths.

INCORRECT	CORRECT
python feninit.default.objdir = '~/Source/mozilla-android/obj-android' python feninit.default.srcroot = '~/Source/mozilla-central/mozilla'	python feninit.default.objdir = '/home/USERNAME/Source/mozilla-android/obj-android' python feninit.default.srcroot = '/home/USERNAME/Source/mozilla-central/mozilla'

Running JimDB

Once JimDB is properly set up, with a moz-gdb directory as described above, running Fennec in GDB is very easy:

 ./moz-gdb/bin/gdb

This will automatically start gdbserver and fennec on the device, and start gdb on your computer.