PariDroid

PariDroid is a port of PARI/GP to Android, started by Charles Boyd and currently maintained by Andreas Enge and Laurent Facq. It is distributed under the GNU General Public License, either version 3 of the licence, or (at your option) any later version (GPLv3+).

Installing PariDroid

Ready to use packages in the .apk format can be found in the download section. They are also available via the F-Droid and the Google Play stores. The remainder of this page describes how to compile the source code for yourself; there is no need to do so if you are happy with the provided binaries.

Privacy Policy.

Installing the Android SDK 26.1.1

The following describes our attempts at installing the latest development environment for Android from the command line. Unfortunately, backwards compatibility does not seem to be a concern for the Android SDK developers: We did not manage to run a recent emulator with Android 3 (API 11) images, which is the earliest version for which PariDroid can still be compiled. Also starting the more modern emulator seems to be incredibly slow. So the next chapter, describing how to install the SDK 24.4.1, is still of interest; this is how we currently develop and test PariDroid.

1. SDK

Download the Android SDK tools, for instance the Linux build 4333796, and unpack it into /usr/local/android-sdk-r26.1.1 (the version 26.1.1 appears in the file package.xml):

cd /tmp
wget http://dl.google.com/android/repository/sdk-tools-linux-4333796.zip
mkdir android-sdk-r26.1.1
cd android-sdk-r26.1.1
unzip ../sdk-tools-linux-4333796.zip
cd ..
su
mv android-sdk-r26.1.1 /usr/local

Add the avdmanager binary to your path, for instance as symbolic link:

export SDK=/usr/local/android-sdk-r26.1.1
su
cd /usr/local/bin
ln -s $SDK/tools/bin/avdmanager

Install Android platform tools by downloading and unpacking a software archive as follows:

cd /tmp
wget http://dl.google.com/android/repository/platform-tools_r29.0.1-linux.zip
unzip platform-tools_r29.0.1-linux.zip
mv platform-tools $SDK/

Add adb to your execution path:

su
cd /usr/local/bin
ln -s $SDK/platform-tools/adb

Install Android build tools by downloading and unpacking a software archive as follows:

cd /tmp
wget http://dl.google.com/android/repository/build-tools_r29.0.1-linux.zip
unzip build-tools_r29.0.1-linux.zip
mkdir $SDK/build-tools
mv android-10 $SDK/build-tools/29.0.1

Add zipalign to your execution path:

su
cd /usr/local/bin
ln -s $SDK/build-tools/29.0.1/zipalign

Install an Android platform by downloading and unpacking a software archive as follows; Android API 11 (Android 3.0) is currently the minimal version required by PariDroid:

cd /tmp
wget http://dl.google.com/android/repository/android-3.0_r02.zip
unzip android-3.0_r02.zip
mkdir $SDK/platforms/
mv android-3.0_r02-linux $SDK/platforms/android-11

The aarch64 architecture appeared for the first time in Android API 21 (Android 5.0); also install this version:

cd /tmp
wget http://dl.google.com/android/repository/android-21_r02.zip
unzip android-21_r02.zip
mv android-5.0.1 $SDK/platforms/android-21

Now we need to download system images for the emulator and install them into the right places; there is one image per Android API and architecture.

For android-11, the system image is already installed in $SDK/platforms/android-11/images; using it to create an avd unfortunately fails. The only image for aarch64 is android-24; this is also the last one for arm. From then on, only images for x86 and x86_64 are available. So android-24 seems like a good choice.

cd /tmp
wget http://dl.google.com/android/repository/sys-img/android/armeabi-v7a-24_r07.zip
unzip armeabi-v7a-24_r07.zip
mkdir -p $SDK/system-images/android-24/default
mv armeabi-v7a $SDK/system-images/android-24/default/
wget http://dl.google.com/android/repository/sys-img/android/arm64-v8a-24_r07.zip
unzip arm64-v8a-24_r07.zip
mv arm64-v8a $SDK/system-images/android-24/default/
wget http://dl.google.com/android/repository/sys-img/android/x86_64-24_r08.zip
unzip x86_64-24_r08.zip
mv x86_64 $SDK/system-images/android-24/default/

2. Emulator

Download and install the emulator as follows:

cd /tmp
wget http://dl.google.com/android/repository/emulator-linux-5839083.zip
unzip emulator-linux-5839083.zip
mv emulator $SDK/

Add emulator to your execution path (there are two potential binaries, one in $SDK/tools and one in $SDK/emulator; the former does not seem to work):

su
cd /usr/local/bin
ln -s $SDK/emulator/emulator

For the emulator to work, we need to create virtual Android devices (avd), one for each combination of Android API and architecture:

avdmanager create avd -k 'system-images;android-24;default;armeabi-v7a' -n android24-arm
avdmanager create avd -k 'system-images;android-24;default;arm64-v8a' -n android24-aarch64
avdmanager create avd -k 'system-images;android-24;default;x86_64' -n android24-x86_64

creates virtual devices for the Android ABI 24 and three different architectures under the names given after the -n parameter, which should be listed when executing

avdmanager list avd

To enable input from the computer keyboard as if it were typed on the telephone, add to the files ~/.android/avd/android24-arm.avd/config.ini (and similarly for the other architectures) the line hw.keyboard=yes .

Start the Android emulator with

emulator -avd android24-arm &

A window opens in which (after a few minutes) a telephone screen is simulated. If for simpler testing purposes you can make do without a window, the command

emulator -avd android24-aarch64 -no-audio -no-window &

starts the emulator faster in command line mode. To see whether the emulator is ready, call

adb logcat

to see tons of start-up messages. The emulator may be stopped with

adb -s emulator-5554 emu kill

The emulators for the arm or aarch64 architectures recommend to install one for x86, which is supposedly 10 times faster. Unfortunately, the latter refuses to start for lacking hardware acceleration with kvm. The aarch64 emulator loops with error messages.

All in all, there does not seem to be any advantage in switching to the more modern SDK.

Installing the Android SDK 24.4.1

1. SDK

Download the Android SDK, for instance the Linux build r24.4.1 (which appears to be the last version containing the tools/ subdirectory and to be independent of Android Studio), and unpack it into /usr/local/android-sdk-r24.4.1:

cd /tmp
wget http://dl.google.com/android/android-sdk_r24.4.1-linux.tgz
tar xvf android-sdk_r24.4.1-linux.tgz
su
mv android-sdk-linux /usr/local/android-sdk-r24.4.1

Add the android and emulator64-arm binaries to your path, for instance as symbolic links:

export SDK=/usr/local/android-sdk-r24.4.1
su
cd /usr/local/bin
ln -s $SDK/tools/android
ln -s $SDK/tools/emulator64-arm

Install Android platform tools by downloading and unpacking a software archive as follows:

cd /tmp
wget http://dl.google.com/android/repository/platform-tools_r29.0.1-linux.zip
unzip platform-tools_r29.0.1-linux.zip
mv platform-tools $SDK/

Install Android build tools by downloading and unpacking a software archive as follows:

cd /tmp
wget http://dl.google.com/android/repository/build-tools_r29.0.1-linux.zip
unzip build-tools_r29.0.1-linux.zip
mkdir $SDK/build-tools
mv android-10 $SDK/build-tools/

The previous steps have populated $SDK/platform-tools and $SDK/build-tools. Add adb and zipalign to your execution path:

su
cd /usr/local/bin
ln -s $SDK/platform-tools/adb
ln -s $SDK/build-tools/android-10/zipalign

Install an Android platform by downloading and unpacking a software archive as follows:

cd /tmp
wget http://dl.google.com/android/repository/android-21_r02.zip
unzip android-21_r02.zip
mv android-5.0.1 $SDK/platforms/

Now we need to download a system image for the emulator and install it into the right place:

cd /tmp
wget http://dl.google.com/android/repository/sys-img/android/armeabi-v7a-21_r04.zip
unzip armeabi-v7a-21_r04.zip
mkdir $SDK/platforms/android-5.0.1/images
mv armeabi-v7a $SDK/platforms/android-5.0.1/images/

2. Emulator

For the emulator to work, we need to create a virtual Android device (avd). First,

android list target

shows one possible target, android-21, which we have installed previously into $SDK/platforms.

android create avd -t android-21 -n android21

now creates a new virtual device with the name android21, which should be listed when executing

android list avd

To enable input from the computer keyboard as if it were typed on the telephone, add to the file ~/.android/avd/android21.avd/config.ini the line hw.keyboard=yes .

Start the Android emulator with

emulator64-arm -avd android21 &

A window opens in which (after a few minutes) a telephone screen is simulated. If for simpler testing purposes you can make do without a window, the command

emulator64-arm -avd android21 -no-audio -no-window &

starts the emulator faster in command line mode. To see whether the emulator is ready, call

adb get-state

which returns device when the emulator is ready (and unknown before). Or wait until

adb wait-for-device

returns. The emulator may be stopped with

adb -s emulator-5554 emu kill

Installing the Android NDK

To later compile and integrate the PARI C library into the project, download the Android NDK; for instance, Linux 64bit r13b. (This is the last version where the include files are still contained in the platforms/ subdirectory, instead of in sysroot/. Version r17c is the last version that ships the GCC cross compiler. Version r18b contains a compiler named gcc, but which in reality is clang.) Unpack it and move it, for instance, to /usr/local/android-ndk-r13b.

Set the environment variable NDK to contain the path to the Android NDK, which is used by our Makefile:

export NDK=/usr/local/android-ndk-r13b

Setting up the PariDroid project

The following steps need to be executed only once. Download PariDroid from its git repository:

git clone http://pari.math.u-bordeaux.fr/git/paridroid.git
cd paridroid/PariDroid

Prepare the Android project:

android update project --target android-21 -s -p .
cd ..

The PARI source code will be fetched automatically from the git server and placed into the ../srclib/pari directory, next to the PariDroid sources, when invoking make for the first time. The Makefile also contains the logic to check out the correct PARI version depending on the PariDroid version number: its first three fields specify the PARI version. If it corresponds to a released version, the corresponding git tag is checked out. Otherwise, the latest git master is fetched.

The Makefile is set up to create an apk in release mode, which is then signed with a debug key. On the first run, this key needs to be created by doing a debug build:

cd PariDroid
ant debug
cd ..

Building PariDroid

A call to

make

configures and compiles the PARI library and compiles the PariDroid project into the package PariDroid-VERSION.apk, signed with a debug key and aligned.

The unsigned and unaligned package resides in PariDroid/bin/PariDroid-release-unsigned.apk, the signed and unaligned package in PariDroid/bin/PariDroid-release-unaligned.apk.

make distclean

removes the generated files. The final package can be tested by installing it in the emulator:

adb install PariDroid-VERSION.apk

After clicking on the application icon on the telephone screen, a click on the PariDroid icon should open the program. To simplify further tests, the icon can be dragged onto the home screen (it will always refer to the latest installed PariDroid instance).

The package can be uninstalled using

adb uninstall fr.ubordeaux.math.paridroid

or, more easily, an installed package can be overwritten with

adb install -r PariDroid-VERSION.apk

For debugging purposes, it may be useful to launch the command

adb logcat

in a separate terminal window.