How to build and install cmocka?

Step into directory containing sources and create build sub-directory.

Step into build directory and execute

$ make


$ sudo make install

Download cmocka

cmocka at GitHub


How to create self-extracting script for Android?

This is useful for consistent updating RIL, applications and configuration file.

Idea is to add compressed binary at the end of executable shell script file.

Step 1

On the build machine create payload directory and copy files into it.

Step 2

Create script installer in that directory which should do installation of components on target platform.

Step 3

Move one level up from payload directory and create decompress script with following content:

echo “”
echo “Self Extracting Installer”
echo “”

# Creates temporary directory.
export TMPDIR=`mktemp -d selfextract.XXXXXX`

# Searches for marker of beginning of binary data.
ARCHIVE=`sed -n ‘/^__ARCHIVE_BELOW__/=’ $0`

# Adds 1 to get next line after the marker.

# Extracts binary data into temporary directory.
tail -n+$ARCHIVE $0 | tar xv -C $TMPDIR

# Stores current directory, goes to the temporary
# directory and starts the install script.

# Returns back and removes temporary directory.
cd $CDIR
rm -rf $TMPDIR

# Prevents executing binary data.
exit 0

# No extra lines should be added after the marker.

Step 4

Create build script having following content:

# Compresses payload data.
cd payload
tar cf ../payload.tar ./*
cd ..

if [ -e “payload.tar” ]; then
# Data aren’t compressed due to lack of gunzip on target platform.
# Concatenates the decompressing script with binary data.
cat decompress payload.tar > selfextract.bsx
echo “payload.tar does not exist”
exit 1

echo “selextract.bsx created”
exit 0

Step 5

Execute build script. Make sure that selfextract.bsx file is created.

Step 6

Copy selfextract.bsx file to target device, change file mode by

# chmod 755 selfextract.bsx

and execute it by

# ./selfextract.bsx

Make sure that files were updated successfully.

Read in more details

Bash Self-Extracting Script

How to make a self-extracting shell script from a TAR archive

Use grep to report back only line numbers

Sed Command in Linux/Unix with examples

Alternative to awk

The main differences from the solution proposed in referenced articles are:

  • sed utility is used instead of awk because the latter is not included in Android distribution by default;
  • compressing by gzip is not used because gunzip utility is not included as well.

How to build Android-x86

Setup procedure

  • Create a build account and define password
sudo useradd -m build
sudo passwd
  • Fully update your environment
sudo apt update
sudo apt upgrade
  • Install all required packages (google build environment spec.)
sudo apt install openjdk-8-jdk git git-core gnupg flex 
     bison gperf build-essential zip curl zlib1g-dev 
     gcc-multilib g++-multilib libc6-dev-i386 
     lib32ncurses5-dev x11proto-core-dev libx11-dev 
     lib32z-dev ccache libgl1-mesa-dev 
     libxml2-utils xsltproc unzip dosfstools
  • Install python-mako
sudo apt install python-mako
  • Install geniso and syslinux
sudo apt install geniso syslinux isolinux 
     syslinux-utils syslinux-efi


  • As build user install google REPO tool
 curl > ~/bin/repo
 chmod a+x ~/bin/repo
  • Init GIT repo
 git config --global
 git config --global
 git config --global build
  • Clone android sources
$ repo init -u 
    -b oreo-x86
$ repo sync --no-tags --no-clone-bundle
  • Cloning other branch
$ repo init -u 
    -b $branch
$ repo sync --no-tags --no-clone-bundle

Build procedure

  • Set source environment and helper functions
source build/
  • Configure target architecture
 lunch android_x86_64-userdebug
  • Initiate build process. In our case we use 8 CPU cores and building an ISO image installable on VirtualBox
m -j8 iso_img 2>&1 | tee compile-01.log

Alternatively you can use following scripts which takes parameter and use it to construct image name

./prebuilts/sdk/tools/jack-admin kill-server
export JACK_SERVER_VM_ARGUMENTS="-Dfile.encoding=UTF-8 
       -XX:+TieredCompilation -Xmx4g"
./prebuilts/sdk/tools/jack-admin start-server
source build/
lunch android_x86_64-userdebug
m -j8 iso_img

# removes all other builds with the same label
rm android_x86_64_7.1_cougar_*_$1.iso

mv out/target/product/x86_64/android_x86_64.iso 
   android_x86_64_7.1_cougar_$(date +'%y%m%d_%H%M%S')_$1.iso

and cleaning output directory

source build/
make clobber

If an error happened like “error: cannot exceed 91 bytes: Android-x86” do following

  • Edit build/tools/
# See PROP_VALUE_MAX in system_properties.h.
# The constant in system_properties.h includes the terminating NUL,
# so we decrease the value by 1 here.
  • Edit bionic/libc/include/sys/system_properties.h
//#define PROP_VALUE_MAX  92
#define PROP_VALUE_MAX  128
  • Edit frameworks/native/cmds/installd/installd_deps.h
//constexpr size_t kPropertyValueMax = 92u;
constexpr size_t kPropertyValueMax = 128u;
  • Do clean rebuild.

Build Issues

Default Jack server resources on 8-gig or less

 Stop Jack server: ./prebuilts/sdk/tools/jack-admin kill-server
 export JACK_SERVER_VM_ARGUMENTS="-Dfile.encoding=UTF-8 
        -XX:+TieredCompilation -Xmx4g"
 Start jack server: ./prebuilts/sdk/tools/jack-admin start-server

How to add new C-application to Android build

Take as an example linmuxcfg application having single c-file.

Step 1

Create file

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)

LOCAL_CFLAGS += -Wall -Werror -Wextra -Wbad-function-cast  -Wmissing-prototypes
LOCAL_CFLAGS += -Wsign-compare -Wmissing-declarations -Wmissing-field-initializers
LOCAL_CFLAGS += -I../../kernel/include

LOCAL_MODULE := linmuxcfg
LOCAL_SRC_FILES := linmuxcfg.c


Step 2

Put the application into folder packages/apps relative the root of Android build chain.



Step 3

Add program (line linmuxcfg) into Android build script:

  • Android 8
    • ./build/make/target/product/
  • Android 7.1

Step 4

Execute make program_name or rebuild Android (the application will be build automatically). Find its binary in build chain by means of find -name program_name.


make linmuxcfg
find -name linmuxcfg

Android Build System