一.编写helloworld.c Android.mk
[root@fontlose jni]# cat hello.c
- #include <stdio.h>
- int main()
- {
- printf("Hello World!\n");
- return 0;
- }
[root@fontlose jni]# cat Android.mk
- LOCAL_PATH:= $(call my-dir)
- include $(CLEAR_VARS)
- LOCAL_SRC_FILES:=hello.c
- LOCAL_MODULE := helloworld
- LOCAL_MODULE_TAGS := optional
- include $(BUILD_EXECUTABLE)
二.编译
1) 使用NDK r5
目录结构 ─ hello
├── jni
├── Android.mk
└── hello.c
- [root@fontlose nativity]# cd hello
- [root@fontlose hello]# export NDK_PROJECT_PATH=`pwd`
- [root@fontlose hello]# ndk-build
- Install : helloworld => libs/armeabi/helloworld
- [root@fontlose hello]# adb push libs/armeabi/helloworld /data
- 44 KB/s (2176 bytes in 0.047s)
- [root@fontlose hello]# adb shell
- / # cd /data
- /data # ls -l
- -rwxrwxrwx root root 2176 2011-08-07 03:01 helloworld
- /data # ./helloworld
- Hello World!
2) 使用通用toolchain
在hello.c目录下
- [root@fontlose jni]# arm-none-linux-gnueabi-gcc -static hello.c -o helloworld
- [root@fontlose jni]# adb push helloworld /data
- 1718 KB/s (581219 bytes in 0.330s)
- [root@fontlose jni]# adb shell
- / # cd /data
- /data # ls -l
- -rwxrwxrwx root root 581219 2011-08-07 03:28 helloworld
- /data # ./helloworld
- Hello World!
Windows: http://www.codesourcery.com/gnu_toolchains/arm/portal/package3400/public/arm-none-linux-gnueabi/arm-2008q3-41-arm-none-linux-gnueabi.exe
Linux: http://www.codesourcery.com/gnu_toolchains/arm/portal/package3399/public/arm-none-linux-gnueabi/arm-2008q3-41-arm-none-linux-gnueabi.bin
3) 在源码环境中编译
1. 在源码development 目录下创建hello目录
- [root@fontlose Android-2.3]# mkdir $Android_Src/development/hello
2.将helloworld.c Android.mk拷贝至hello目录下
3. [root@fontlose Android-2.3]# . build/envsetup.sh
4. [root@fontlose Android-2.3]# mmm development/hello/
- ============================================
- PLATFORM_VERSION_CODENAME=REL
- PLATFORM_VERSION=2.3.2
- TARGET_PRODUCT=generic
- TARGET_BUILD_VARIANT=eng
- TARGET_SIMULATOR=
- TARGET_BUILD_TYPE=release
- TARGET_BUILD_APPS=
- TARGET_ARCH=arm
- HOST_ARCH=x86
- HOST_OS=linux
- HOST_BUILD_TYPE=release
- BUILD_ID=GRH78C
- ============================================
- make: 进入目录“/opt/FriendlyARM/mini6410/android/Android-2.3”
- target thumb C: helloworld <= development/hello/hello.c
- target Executable: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
- target Non-prelinked: helloworld (out/target/product/generic/symbols/system/bin/helloworld)
- target Strip: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
- Install: out/target/product/generic/system/bin/helloworld
- make: 离开目录“/opt/FriendlyARM/mini6410/android/Android-2.3”
5.编译完成执行文件在out/target/product/generic/symbols/system/bin/helloworld
下载至设备
- [root@fontlose Android-2.3]# adb push out/target/product/generic/symbols/system/bin/helloworld /data
- 135 KB/s (7608 bytes in 0.054s)
- [root@fontlose Android-2.3]# adb shell
- / # cd /data
- /data # ls -l
- -rwxrwxrwx root root 7608 2011-08-07 03:49 helloworld
- /data # ./helloworld
- Hello World!
4) 使用源码自带Toolchain
在这之前要把上一步中的helloworld模块clean:
- [root@fontlose Android-2.3]# make clean-helloworld
使用showcommands选项重新编译helloworld,查看具体命令,从输出命令行可以看到,Android编译环境所用的交叉编译工具链是prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-gcc。
- [root@fontlose Android-2.3]# make helloworld showcommands
利用上面输出的编译命令,简化来手工编译helloworld程序,先手工删除上次编译得到的helloworld程序:
- [root@fontlose Android-2.3]# rm out/target/product/generic/system/bin/helloworld
gcc编译,生成目标文件
- [root@fontlose Android-2.3]# prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-gcc -I development/hello -I out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates -I dalvik/libnativehelper/include/nativehelper -I system/core/include -I hardware/libhardware/include -I hardware/libhardware_legacy/include -I hardware/ril/include -I dalvik/libnativehelper/include -I frameworks/base/include -I frameworks/base/opengl/include -I frameworks/base/native/include -I external/skia/include -I out/target/product/generic/obj/include -I bionic/libc/arch-arm/include -I bionic/libc/include -I bionic/libstdc++/include -I bionic/libc/kernel/common -I bionic/libc/kernel/arch-arm -I bionic/libm/include -I bionic/libm/include/arch/arm -I bionic/libthread_db/include -c -fno-exceptions -Wno-multichar -msoft-float -fpic -ffunction-sections -funwind-tables -fstack-protector -Wa,--noexecstack -Werror=format-security -fno-short-enums -march=armv5te -mtune=xscale -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ -include system/core/include/arch/linux-arm/AndroidConfig.h -I system/core/include/arch/linux-arm/ -Wno-psabi -mthumb-interwork -DANDROID -fmessage-length=0 -W -Wall -Wno-unused -Winit-self -Wpointer-arith -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -DNDEBUG -g -Wstrict-aliasing=2 -finline-functions -fno-inline-functions-called-once -fgcse-after-reload -frerun-cse-after-loop -frename-registers -DNDEBUG -UDEBUG -mthumb -Os -fomit-frame-pointer -fno-strict-aliasing -finline-limit=64 -MD -o out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o development/hello/hello.c
生成可执行文件:
- [root@fontlose Android-2.3]# prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-g++ -nostdlib -Bdynamic -Wl,-T,build/core/armelf.x -Wl,-dynamic-linker,/system/bin/linker -Wl,--gc-sections -Wl,-z,nocopyreloc -o out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld -Lout/target/product/generic/obj/lib -Wl,-rpath-link=out/target/product/generic/obj/lib -lc -lstdc++ -lm out/target/product/generic/obj/lib/crtbegin_dynamic.o out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o -Wl,-z,noexecstack -Wl,--no-undefined prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/../lib/gcc/arm-eabi/4.4.3/libgcc.a out/target/product/generic/obj/lib/crtend_android.o
使用了out/host/linux-x86/bin/soslim工具进行STRIP
- [root@fontlose Android-2.3]# out/host/linux-x86/bin/soslim --strip --shady --quiet out/target/product/generic/symbols/system/bin/helloworld --outfile out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld
- [root@fontlose Android-2.3]# adb push out/target/product/generic/symbols/system/bin/helloworld /data
- 145 KB/s (7608 bytes in 0.051s)
- [root@fontlose Android-2.3]# adb shell
- / # cd /data/
- /data # ls -l
- -rwxrwxrwx root root 7608 2011-08-07 04:14 helloworld
- /data # ./helloworld
- Hello World!
Android并没有采用glibc作为C库,而是采用了Google自己开发的Bionic Libc,通用的Toolchain用来编译和移植Android 的Linux内核是可行的,因为内核并不需要C库,但是开发Android的应用程序时,其他Toolchain编译的应用程序只能采用静态编译的方式才能运行,使用静态方式编译出来的执行文件都比较大。