Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/akavel/hellomello

Experiments with writing Android apps in Nim
https://github.com/akavel/hellomello

android apk dalvik dex hello-world jni minimal nim standalone

Last synced: 3 months ago
JSON representation

Experiments with writing Android apps in Nim

Awesome Lists containing this project

README 

        
HelloWorld.apk built with Nim and no Android Studio

===================================================






To build the project, you will currently need the following prerequisites:



 - [Nim compiler](https://nim-lang.org/install.html)

 - [Go compiler](https://golang.org/dl/) (TODO: remove this dependency —

   at least provide prebuilt binaries of *apksigner*)

 - [Android NDK][ndk] (the elephant in the room...)

    - *standalone* toolchain — just

      [download][ndk] and unpack

      somewhere, no installation required afterwards (still, ~2.5GB unpacked)

 - ...and: NO Java, NO JRE, NO Android Studio, NO Android SDK! 🎉



[ndk]: https://developer.android.com/ndk/downloads



Build Steps

-----------



1. 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 ..



2. Assemble the Dalvik bytecode (required to wrap the JNI library), using [dali](https://github.com/akavel/dali):



       $ git clone https://github.com/akavel/dali

       $ cd dali

       $ nim c jni_hello.nim

       $ ./jni_hello > ../hellomello/classes.dex

       $ cd ..



3. Compile the manifest file to binary format, using [marco](https://github.com/akavel/marco):



       $ git clone https://github.com/akavel/marco

       $ cd marco

       $ nimble build

       $ cd ../hellomello

       $ ../marco/marco < AndroidManifest0.xml > AndroidManifest.xml



4. 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 ..



5. Sign the .apk, using [apksigner](https://github.com/akavel/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



6. ...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](https://github.com/google/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.](http://akavel.com)*  

*2019-05-06*