hello

In this note, we describe how to build an executable, how to create an emulator, and how to run the executable in the emulator via adb push, adb shell.

./code/hello/hello.cc
1#include <iostream>
2
3int main() {
4  std::cout << "hello world\n";
5  return 0;
6}
./code/hello/CMakeLists
1cmake_minimum_required(VERSION 3.8)
2
3project(hello)
4
5add_executable(hello hello.cc)

x86

export ANDROID_NDK_ROOT=/ceph-fj/fangjun/software/android-ndk
cmake -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK_ROOT/build/cmake/android.toolchain.cmake -DANDROID_ABI=x86 ..
Other values:

  • -DANDROID_ABI="arm64-v8a"

  • -DANDROID_ABI="armeabi-v7a"

  • -DANDROID_ARM_NEON=ON

  • -DANDROID_PLATFORM=android-21

  • -DANDROID_PLATFORM=android-24

$ sdkmanager --list | grep system-images | grep x86 | grep android-28
$ sdkmanager "system-images;android-28;default;x86"

$ which avdmanager
/ceph-fj/fangjun/software/android-sdk/cmdline-tools/latest/bin/avdmanage

$ avdmanager create avd --help
$ -k --package  : Package path of the system image for this AVD
#                 (e.g., 'system-images;android-19;google_apis;x86').
# -n --name     : Name of the new AVD [required]
# -b --abi      : The ABI to use for the AVD. The default is to auto-select
#                 the ABI if the platform has only one ABI for its system images
# -g --tag      : The sys-img tag to use for the AVD. The default is to
#                 auto-select if the platform has only one tag for its system
#                 images
$ avdmanager create avd -k "system-images;android-28;default;x86" -n hello -b x86 -g default
# Use the default option [no] when it prompts:
#  Do you wish to create a custom hardware profile? [no]
#
$ avdmanager delete avd -n hello # to delete it

$ avdmanager list avd
Available Android Virtual Devices:
    Name: hello
    Path: /root/fangjun/.android/avd/hello.avd
  Target: Default Android System Image
          Based on: Android 9.0 (Pie) Tag/ABI: default/x86
  Sdcard: 512 MB

emulator -avd hello -no-window  -no-accel # then, open a new terminal

$ adb devices

* daemon not running; starting now at tcp:5037
* daemon started successfully
List of devices attached
emulator-5554   offline

# push the binary from code/hello/build/hello

adb push ./code/hello/build/hello /sdcard # not able to use chmod +x in it
adb push ./code/hello/build/hello /data/local
adb shell /data/local/hello
adb shell
generic_x86:/ #

generic_x86:/ # ./data/local/hello
hello world