使用Android NDK中的独立toolchain来开发C/C++程序

 

从网上可以找到一些ARM toolchain，但是由于Android系统使用的不是glibc而是Bionic libc。因此只能使用静态编译程序。

其实Android的NDK自带了toolchain，但是不能直接使用NDK目录内的toolchain，否则会出现找不到crtbegin_dynamic.o文件。

即使用-L指定目录或者直接放到gcc命令行也还是提示该文件找不到。（参考最后附上的链接）。

其实Android NDK提供了脚本来剥离出单独的toolchain，脚本的名字叫make-standalone-toolchain.sh

1. 下载Android NDK

http://developer.android.com/sdk/ndk/index.html

我用的是android-ndk-r6b

2. 提取toolchain

可以参考文档docs/STANDALONE-TOOLCHAIN.html

在linux系统中解压NDK，假设解压到/opt;

cd /opt/android-ndk-r6b/

build/tools/make-standalone-toolchain.sh --platform=android-8

expr: warning: unportable BRE: `^\\([^\\-].*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\(--[^=]*\\)=.*$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^--[^=]*=\\(.*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
Auto-config: --toolchain=arm-linux-androideabi-4.4.3
Copying prebuilt binaries...
Copying sysroot headers and libraries...
Copying libstdc++ headers and libraries...
expr: warning: unportable BRE: `^\\([^\\-].*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\(--[^=]*\\)=.*$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\(--.*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\([^\\-].*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\([^\\-].*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\([^\\-].*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^\\(--[^=]*\\)=.*$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
expr: warning: unportable BRE: `^--[^=]*=\\(.*\\)$': using `^' as the first character
of the basic regular expression is not portable; it is being ignored
Creating package file: /tmp/ndk-hansel/arm-linux-androideabi-4.4.3.tar.bz2
Cleaning up...
Done.

有一些警告没有关系，最终得到的是一个压缩包 /tmp/ndk-hansel/arm-linux-androideabi-4.4.3.tar.bz2

注意：这个是我的Linux机器上的目录。

3. 解压单独的toolchain

可以解压到任意目录，这里假设为/opt/

4.写个hello world 程序试试

hello.c

#include <stdlib.h>
#include <stdio.h>


int main(int argc, char* argv[])
{
printf("Hello Andriod.\n");
return 0;
}

#include <stdlib.h>
#include <stdio.h>


int main(int argc, char* argv[])
{
  printf("Hello Andriod.\n");
  return 0;
}

Makefile

export PATH:=/opt/android/arm-linux-androideabi-4.4.3/bin:${PATH}
CROSS_COMPILE=arm-linux-androideabi-
CC=$(CROSS_COMPILE)gcc
LD=$(CROSS_COMPILE)ld

PROG=hello
OBJS=hello.o

$(PROG):$(OBJS)
$(CC) $(LDFLAGS) -o $@ $(OBJS)

%.o:%.c
$(CC) -c $(CFLAGS) $< -o $@

clean:
rm -rf *.o $(PROG)

export PATH:=/opt/android/arm-linux-androideabi-4.4.3/bin:${PATH}
CROSS_COMPILE=arm-linux-androideabi-
CC=$(CROSS_COMPILE)gcc
LD=$(CROSS_COMPILE)ld

PROG=hello
OBJS=hello.o

$(PROG):$(OBJS)
	$(CC) $(LDFLAGS) -o $@ $(OBJS) 

%.o:%.c
	$(CC) -c $(CFLAGS) $< -o $@

clean:
	rm -rf *.o $(PROG)

编译：

make

可以得到hello可执行文件。

$ file hello
hello: ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), not stripped

可见是动态链接的。

上传到手机里执行。如果用数据线连接了手机，而且安装了Android SDK，可以使用adb命令。

adb push hello /system/sbin/hello

adb shell chmod 777 /system/sbin/hello
adb shell /system/sbin/hello

如果没有SDK，可以在手机里安装一个QuickSSHd程序，通过WiFi用Putty之类的软件连接到手机终端。通过SFTP来传送文件。

# ./hello
Hello Andriod.

注意： 手机需要有root权限

参考：

http://groups.google.com/group/android-ndk/browse_thread/thread/7506768ccf52cea2?pli=1