Experiments with writing Android apps in Nim
To build the project, you will currently need the following prerequisites:
Compile the native JNI code, using Nim + Android NDK:
$ git clone https://github.com/akavel/hellomello
# Edit `nim.cfg`: change `--clang.path=...` to a correct path to clang in your Android NDK directory.
# Also: remove `.cmd` suffixes in `nim.cfg` if you are on Linux.
$ cd hellomello
$ nim c --app:lib --os:android --cpu=arm -d:noSignalHandler --hint[CC]:on hello.nim
$ mkdir lib
$ mkdir lib/armeabi-v7a
$ mv libhello.so lib/armeabi-v7a/libhello-mello.so
$ cd ..
Assemble the Dalvik bytecode (required to wrap the JNI library), using dali:
$ git clone https://github.com/akavel/dali
$ cd dali
$ nim c jni_hello.nim
$ ./jni_hello > ../hellomello/classes.dex
$ cd ..
Compile the manifest file to binary format, using marco:
$ git clone https://github.com/akavel/marco
$ cd marco
$ nimble build
$ cd ../hellomello
$ ../marco/marco < AndroidManifest0.xml > AndroidManifest.xml
Build an unsigned .apk, using OS-provided zip archiver:
$ zip -r unsigned.apk classes.dex lib/ AndroidManifest.xml
adding: classes.dex (172 bytes security) (deflated 44%)
adding: lib/ (192 bytes security) (stored 0%)
adding: lib/armeabi-v7a/ (192 bytes security) (stored 0%)
adding: lib/armeabi-v7a/libhello-mello.so (172 bytes security) (deflated 60%)
adding: AndroidManifest.xml (172 bytes security) (stored 0%)
$ cd ..
Sign the .apk, using apksigner tool written in Go:
$ git clone https://github.com/akavel/apksigner
$ cd apksigner
$ go build
$ cd ../hellomello
$ ../apksigner/apksigner -i unsigned.apk -o hello.apk -k key.pk8 -c key.x509.pem
$ unzip -l hello.apk
Archive: hello.apk
Length Date Time Name
-------- ---- ---- ----
282 00-00-80 00:00 META-INF/MANIFEST.MF
335 00-00-80 00:00 META-INF/CERT.SF
436 00-00-80 00:00 META-INF/CERT.EC
14 06-05-19 22:30 AndroidManifest.xml
1060 06-05-19 22:29 classes.dex
149348 06-05-19 22:28 lib/armeabi-v7a/libhello-mello.so
-------- -------
151475 6 files
...aaand you should have a hello.apk
file now, ready to be installed
on an ARM-based Android device. Worked For Me™... In case of problems
installing or opening the apk on your device, try running adb logcat
(yep,
that requires Android Studio... or you could try
python-adb). I suggest searching for
"InstallInstall" and "InstallFail" messages, verifier/verification messages,
and Java-like exception stack traces. You're welcome to post your problems as
issues on this repository, but I can't promise I will be able to help you in
any way. We can treat them as "observations" or "reports". Maybe someone else
will come by and suggest some steps for future experimenters.
/Mateusz Czapliński.
2019-05-06