How to compile C code using NDK for Android Device (ARM)? - c

Question

I need to perform the following steps:
write a simple counter that keeps resetting itself after overflow in C/C++
compile and push that code into the phone via ADB
run it as a regular executable in background via ADB shell
how to compile the above C code using NDK toolchain? I found a couple of similar links but none of them give simple and complete steps to do so.
If there is a link with complete steps please do refer me to the same.
Compile Environment: Ubuntu, compile should be done via console not any IDE

Answer 1

You're right, I made a mistake, I had not even tested it and gave me the
same error, is due to the entry point of the "main", as this has not
changed but I hope this works for you. Anyway check the symbol table "nm",
the real-time execution "strace", you can even use gdbserver.
#include <stdio.h>
int main (int argc, char *argv[])
{
printf ("hello world");
return 0;
}
export NDK_ROOT=your_ndk_path
export PATH=$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86/bin:$PATH
export CC=arm-linux-androideabi-gcc
export LD=arm-linux-androideabi-ld
arm-linux-androideabi-gcc -I$NDK_ROOT/platforms/android-18/arch-arm/usr/include -Wl,-rpath-link=$NDK_ROOT/platforms/android-18/arch-arm/usr/lib -Wl,-L$NDK_ROOT/platforms/android-18/arch-arm/usr/lib -Wl,-lc -o test test.c
If ld return with erros like "... ld: error: cannot open... : No such file or directory"
try this for your losed files:
ln -s $NDK_ROOT/platforms/android-18/arch-arm/usr/lib/crtend_android.o
ln -s $NDK_ROOT/platforms/android-18/arch-arm/usr/lib/crtbegin_dynamic.o

Answer 2

I use gcc4.8 and android API-level18
usin this you can try:
First way using command line.
export NDK_ROOT=your_ndk_path
export PATH=$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86/bin:$PATH
export CC=arm-linux-androideabi-gcc
export LD=arm-linux-androideabi-ld
export CPPFLAGS=-I$NDK_ROOT/platforms/android-18/arch-arm/usr/include
export CFLAGS="-nostdlib" LDFLAGS="-Wl,-rpath-link=$NDK_ROOT/platforms/android-18/arch-arm/usr/lib/ -L$NDK_ROOT/platforms/android-18/arch-arm/usr/lib"
export LIBS="-lc"
arm-linux-androideabi-gcc -nostdlib -o test test.c
If run "file test" you should see this:
test: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, not stripped
Second way using autotools.
export PATH=$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86/bin:$PATH
./configure --host=arm-linux-androideabi CC=arm-linux-androideabi-gcc LD=arm-linux-androideabi-ld CPPFLAGS="-I$NDK_ROOT/platforms/android-18/arch-arm/usr/include" CFLAGS="-nostdlib" LDFLAGS="-Wl,-rpath-link=$NDK_ROOT/platforms/android-18/arch-arm/usr/lib/ -L$NDK_ROOT/platforms/android-18/arch-arm/usr/lib" LIBS="-lc"
make
http://embelinux.blogspot.com/2013/09/autotools1-hola-mundo-la-autotools.html
Third way using android developers ndk full feature.
Read Android.mk file syntax specification. This document describes the
syntax of Android.mk build file written to describe your C and C++ source
files to the Android NDK.
http://www.kandroid.org/ndk/docs/ANDROID-MK.html

Answer 3

gdbserver is to debug an application running on the Android device and can
control gdb from the PC using a TCP connection. gdb (The GNU Debugger)
need the debugging symbols.
When you compile an application the compiler puts all the symbols defined
in something called as symbol table, the problem was not link to rtbegin_dynamic.o,
crtend_android.o that if you specify -nostdlib option the program is created but no work (Table Simbol empty)
nm (list symbols from object files) eg: nm test
gcc is not a compiler, it is a driver that controls the execution
of other applications that are what make the job
for example try invoque the compiler using -### as unique option for see details
LDFLAGS: are the flags for the linker
CFLAGS: are the flags to the compiler (not links)
Anyway if you are new to the compilation, even in cross compiling strongly
recommend you use the Android.mk way
Sorry for my English ;)

Answer 4

#Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
#module name
LOCAL_MODULE := test
#src
LOCAL_SRC_FILES := test.c
#build executable
include $(BUILD_EXECUTABLE)
export PATH=path_to_ndk_root:$PATH
export NDK_PROJECT_PATH=.
ndk-build APP_BUILD_SCRIPT=Android.mk