How To: Cross compile Golang for Android

Update 2022:

Since this was back in the Golang 1.4 days and I have now had reason to do this again, the steps are a little easier. For Golang 1.19 I made a handy Makefile

Here is a handy Makefile that will build a 32bit binary on an Ubuntu22.04 box

NDK=/usr/lib/android-sdk/ndk-bundle/
.PHONY: linux

# if you are fancy and have an NDK installed
android:
	CC="$(NDK)/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang" \
	CC_FOR_TARGET="$(NDK)/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang" \
	CGO_ENABLED=1 \
	GOOS=android \
	GOARCH=arm \
	go build

setup:
	sudo apt install google-android-ndk-installer

To build for the android platform (GOOS=android) you need to do the following:

I placed all the downloads into ~/dev

1. Get a copy of Golang >= version 1.4 from https://golang.org/dl/
   • Unpack it into ~/dev
2. Grab the latest copy of the Android NDK from https://developer.android.com/tools/sdk/ndk/index.html
   • Make it executable and run it (it unpacks into the current folder, so ~/dev)
3. Time to get a copy of our platform NDK.

   export NDK_ROOT=~/dev/ndk-toolchain
   ./android-ndk-r10c/build/tools/make-standalone-toolchain.sh --platform=android-16 --install-dir=$NDK_ROOT
       

4. Now we need to build the Golang toolchain, cd into ~/dev/go/src

   export NDK_CC=~/dev/ndk-toolchain/bin/arm-linux-androideabi-gcc
   CC_FOR_TARGET=$NDK_CC GOOS=android GOARCH=arm GOARM=7 ./make.bash
       

5. Now we can cross compile
   • You can put the following into a build.sh file

   • export NDK_TOOLCHAIN=~/dev/ndk-toolchain
     export CC=$NDK_TOOLCHAIN/bin/arm-linux-androideabi-gcc
     export GOROOT=~/dev/go
     export GOPATH=`pwd`
     export GOOS=android
     export GOARCH=arm
     export GOARM=7
     export CGO_ENABLED=1
     
     GO="$GOROOT/bin/go"
     
     $GO build -x main.go
     

   • Once you have made it executable (chmod +x build.sh) you can ./build.sh to build your app.