Android编译环境(1) - 编译Native …
2013-12-19 20:38
134 查看
Android编译环境本身比较复杂,且不像普通的编译环境:只有顶层目录下才有Makefile文件,而其他的每个component都使用统一标准的
Android.mk.
Android.mk文件本身是比较简单的,不过它并不是我们熟悉的Makefile,而是经过了Android自身编译系统的很多处理,因此要真正理清
楚其中的联系还比较复杂,不过这种方式的好处在于,编写一个新的Android.mk来给Android增加一个新的Component会比较简单。
编译Java程序可以直接采用Eclipse的集成环境来完成,这里就不重复了。我们主要针对C/C++来说明,下面通过一个小例子来说明,如何在Android
中增加一个C程序的Hello World:
1. 在$(YOUR_ANDROID)/development
目录下创建hello目录,其中$(YOUR_ANDROID)指Android源代码所在的目录。
- # mkdir $(YOUR_ANDROID)/development/hello
2.
在$(YOUR_ANDROID)/development/hello/目录编写hello.c文件,hello.c的内容当然就是经典的HelloWorld程序:
#include <stdio.h>
int main()
{
printf("Hello World!/n");
return 0;
}
3. 在$(YOUR_ANDROID)/development/hello/目录编写Android.mk文件。这是Android
Makefile的标准命名,不要更改。Android.mk文件的格式和内容可以参考其他已有的Android.mk文件的写法,针对
helloworld程序的Android.mk文件内容如下:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES:= /
hello.c
LOCAL_MODULE := helloworld
include $(BUILD_EXECUTABLE)
注意上面LOCAL_SRC_FILES用来指定源文件;,LOCAL_MODULE指定要编译的模块的名字,下一步骤编译时就要用到;include
$(BUILD_EXECUTABLE)表示要编译成一个可执行文件,如果想编译成动态库则可用BUILD_SHARED_LIBRARY,这些可以
在$(YOUR_ANDROID)/build/core/config.mk查到。
4. 回到Android源代码顶层目录进行编译:
# cd $(YOUR_ANDROID) && make
helloworld
注意make
helloworld中的目标名helloworld就是上面Android.mk文件中由LOCAL_MODULE指定的模块名。编译结果如下:
target thumb C: helloworld <=
development/hello/hello.c
target Executable: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
target Non-prelinked: helloworld
(out/target/product/generic/symbols/system/bin/helloworld)
target Strip: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
Install: out/target/product/generic/system/bin/helloworld
5.如上面的编译结果所示,编译后的可执行文件存放在out/target/product/generic/system/bin/helloworld,通过”adb
push”将它传送到模拟器上,再通过”adb
shell”登录到模拟器终端,就可以执行了
上一篇中(即《Android编译环境(1) -
编译Native
C的helloworld模块》),我们试用了通过标准的Android.mk文件来编译C模块,下面我们来试试如何直接运用gcc命令行来编译,从而了解Android编译环境的细节。
Android编译环境提供了”showcommands”选项来显示编译命令行,我们可以通过打开这个选项来查看一些编译时的细节。当然,在这之前要把上一篇中的helloworld模块clean:
# make clean-helloworld
上面的“make clean-$(LOCAL_MODULE)”是Android编译环境提供的make clean的方式。
接下来使用showcommands选项重新编译helloworld:
# make helloworld showcommands
build/core/product_config.mk:229: WARNING: adding test OTA
key
target thumb C: helloworld <=
development/hello/hello.c
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc -I
system/core/include -I hardware/libhardware/include -I
hardware/ril/include -I dalvik/libnativehelper/include -I
frameworks/base/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 -I
development/hello -I
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates
-c -fno-exceptions -Wno-multichar -march=armv5te -mtune=xscale
-msoft-float -fpic -mthumb-interwork -ffunction-sections
-funwind-tables -fstack-protector -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 -DANDROID
-fmessage-length=0 -W -Wall -Wno-unused -DSK_RELEASE -DNDEBUG -O2
-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
target Executable: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/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,--no-undefined
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/../lib/gcc/arm-eabi/4.2.1/interwork/libgcc.a
out/target/product/generic/obj/lib/crtend_android.o
target Non-prelinked: helloworld
(out/target/product/generic/symbols/system/bin/helloworld)
out/host/linux-x86/bin/acp -fpt
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
out/target/product/generic/symbols/system/bin/helloworld
target Strip: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
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
Install: out/target/product/generic/system/bin/helloworld
out/host/linux-x86/bin/acp -fpt
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld
out/target/product/generic/system/bin/helloworld
从上面的命令行可以看到,Android编译环境所用的交叉编译工具链是prebuilt/linux-x86/toolchain
/arm-eabi-4.2.1/bin/arm-eabi-gcc,-I和-L参数指定了所用的C库头文件和动态库文件路径分别是bionic
/libc/include
和out/target/product/generic/obj/lib,其他还包括很多编译选项以及-D所定义的预编译宏。
我们可以利用上面的编译命令,稍加简化来手工编译helloworld程序。先手工删除上次编译得到的helloworld程序:
# rm
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o
# rm out/target/product/generic/system/bin/helloworld
再用gcc编译,生成目标文件:
# prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc -I
bionic/libc/arch-arm/include -I bionic/libc/include -I
bionic/libc/kernel/common -I bionic/libc/kernel/arch-arm -c
-fno-exceptions -Wno-multichar -march=armv5te -mtune=xscale
-msoft-float -fpic -mthumb-interwork -ffunction-sections
-funwind-tables -fstack-protector -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 -DANDROID
-fmessage-length=0 -W -Wall -Wno-unused -DSK_RELEASE -DNDEBUG -O2
-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
与Android.mk编译参数比较,上面主要减少了不必要的-I参数。
接下来生成可执行文件:
# prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc
-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 -lm
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o
out/target/product/generic/obj/lib/crtbegin_dynamic.o
-Wl,--no-undefined
./prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/../lib/gcc/arm-eabi/4.2.1/interwork/libgcc.a
out/target/product/generic/obj/lib/crtend_android.o
这里值得留意的是参数“-Wl,-dynamic-linker,/system/bin/linker”,它指定了Android专用的动态链接器/system/bin/linker,而不是通常所用的ld.so。
生成的可执行程序可用file和readelf命令来查看一下:
# file
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld:
ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically
linked (uses shared libs), not stripped
# readelf -d
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
|grep NEEDED
0x00000001 (NEEDED) Shared library: [libc.so]
0x00000001 (NEEDED) Shared library: [libm.so]
这是ARM格式的动态链接可执行文件,运行时需要libc.so和libm.so。“not
stripped”表示它还没被STRIP。嵌入式系统中为节省空间通常将编译完成的可执行文件或动态库进行STRIP,即去掉其中多余的符号表信息。在
前面“make helloworld
showcommands”命令的最后我们也可以看到,Android编译环境中使用了out/host/linux-x86/bin/soslim工具
进行STRIP。
有关Android Toolchain的其他一些内容可参考:Android Toolchain与Bionic
Libc
Android.mk.
Android.mk文件本身是比较简单的,不过它并不是我们熟悉的Makefile,而是经过了Android自身编译系统的很多处理,因此要真正理清
楚其中的联系还比较复杂,不过这种方式的好处在于,编写一个新的Android.mk来给Android增加一个新的Component会比较简单。
编译Java程序可以直接采用Eclipse的集成环境来完成,这里就不重复了。我们主要针对C/C++来说明,下面通过一个小例子来说明,如何在Android
中增加一个C程序的Hello World:
1. 在$(YOUR_ANDROID)/development
目录下创建hello目录,其中$(YOUR_ANDROID)指Android源代码所在的目录。
- # mkdir $(YOUR_ANDROID)/development/hello
2.
在$(YOUR_ANDROID)/development/hello/目录编写hello.c文件,hello.c的内容当然就是经典的HelloWorld程序:
#include <stdio.h>
int main()
{
printf("Hello World!/n");
return 0;
}
3. 在$(YOUR_ANDROID)/development/hello/目录编写Android.mk文件。这是Android
Makefile的标准命名,不要更改。Android.mk文件的格式和内容可以参考其他已有的Android.mk文件的写法,针对
helloworld程序的Android.mk文件内容如下:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES:= /
hello.c
LOCAL_MODULE := helloworld
include $(BUILD_EXECUTABLE)
注意上面LOCAL_SRC_FILES用来指定源文件;,LOCAL_MODULE指定要编译的模块的名字,下一步骤编译时就要用到;include
$(BUILD_EXECUTABLE)表示要编译成一个可执行文件,如果想编译成动态库则可用BUILD_SHARED_LIBRARY,这些可以
在$(YOUR_ANDROID)/build/core/config.mk查到。
4. 回到Android源代码顶层目录进行编译:
# cd $(YOUR_ANDROID) && make
helloworld
注意make
helloworld中的目标名helloworld就是上面Android.mk文件中由LOCAL_MODULE指定的模块名。编译结果如下:
target thumb C: helloworld <=
development/hello/hello.c
target Executable: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
target Non-prelinked: helloworld
(out/target/product/generic/symbols/system/bin/helloworld)
target Strip: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
Install: out/target/product/generic/system/bin/helloworld
5.如上面的编译结果所示,编译后的可执行文件存放在out/target/product/generic/system/bin/helloworld,通过”adb
push”将它传送到模拟器上,再通过”adb
shell”登录到模拟器终端,就可以执行了
上一篇中(即《Android编译环境(1) -
编译Native
C的helloworld模块》),我们试用了通过标准的Android.mk文件来编译C模块,下面我们来试试如何直接运用gcc命令行来编译,从而了解Android编译环境的细节。
Android编译环境提供了”showcommands”选项来显示编译命令行,我们可以通过打开这个选项来查看一些编译时的细节。当然,在这之前要把上一篇中的helloworld模块clean:
# make clean-helloworld
上面的“make clean-$(LOCAL_MODULE)”是Android编译环境提供的make clean的方式。
接下来使用showcommands选项重新编译helloworld:
# make helloworld showcommands
build/core/product_config.mk:229: WARNING: adding test OTA
key
target thumb C: helloworld <=
development/hello/hello.c
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc -I
system/core/include -I hardware/libhardware/include -I
hardware/ril/include -I dalvik/libnativehelper/include -I
frameworks/base/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 -I
development/hello -I
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates
-c -fno-exceptions -Wno-multichar -march=armv5te -mtune=xscale
-msoft-float -fpic -mthumb-interwork -ffunction-sections
-funwind-tables -fstack-protector -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 -DANDROID
-fmessage-length=0 -W -Wall -Wno-unused -DSK_RELEASE -DNDEBUG -O2
-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
target Executable: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/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,--no-undefined
prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/../lib/gcc/arm-eabi/4.2.1/interwork/libgcc.a
out/target/product/generic/obj/lib/crtend_android.o
target Non-prelinked: helloworld
(out/target/product/generic/symbols/system/bin/helloworld)
out/host/linux-x86/bin/acp -fpt
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
out/target/product/generic/symbols/system/bin/helloworld
target Strip: helloworld
(out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
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
Install: out/target/product/generic/system/bin/helloworld
out/host/linux-x86/bin/acp -fpt
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld
out/target/product/generic/system/bin/helloworld
从上面的命令行可以看到,Android编译环境所用的交叉编译工具链是prebuilt/linux-x86/toolchain
/arm-eabi-4.2.1/bin/arm-eabi-gcc,-I和-L参数指定了所用的C库头文件和动态库文件路径分别是bionic
/libc/include
和out/target/product/generic/obj/lib,其他还包括很多编译选项以及-D所定义的预编译宏。
我们可以利用上面的编译命令,稍加简化来手工编译helloworld程序。先手工删除上次编译得到的helloworld程序:
# rm
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o
# rm out/target/product/generic/system/bin/helloworld
再用gcc编译,生成目标文件:
# prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc -I
bionic/libc/arch-arm/include -I bionic/libc/include -I
bionic/libc/kernel/common -I bionic/libc/kernel/arch-arm -c
-fno-exceptions -Wno-multichar -march=armv5te -mtune=xscale
-msoft-float -fpic -mthumb-interwork -ffunction-sections
-funwind-tables -fstack-protector -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 -DANDROID
-fmessage-length=0 -W -Wall -Wno-unused -DSK_RELEASE -DNDEBUG -O2
-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
与Android.mk编译参数比较,上面主要减少了不必要的-I参数。
接下来生成可执行文件:
# prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/arm-eabi-gcc
-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 -lm
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o
out/target/product/generic/obj/lib/crtbegin_dynamic.o
-Wl,--no-undefined
./prebuilt/linux-x86/toolchain/arm-eabi-4.2.1/bin/../lib/gcc/arm-eabi/4.2.1/interwork/libgcc.a
out/target/product/generic/obj/lib/crtend_android.o
这里值得留意的是参数“-Wl,-dynamic-linker,/system/bin/linker”,它指定了Android专用的动态链接器/system/bin/linker,而不是通常所用的ld.so。
生成的可执行程序可用file和readelf命令来查看一下:
# file
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld:
ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically
linked (uses shared libs), not stripped
# readelf -d
out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld
|grep NEEDED
0x00000001 (NEEDED) Shared library: [libc.so]
0x00000001 (NEEDED) Shared library: [libm.so]
这是ARM格式的动态链接可执行文件,运行时需要libc.so和libm.so。“not
stripped”表示它还没被STRIP。嵌入式系统中为节省空间通常将编译完成的可执行文件或动态库进行STRIP,即去掉其中多余的符号表信息。在
前面“make helloworld
showcommands”命令的最后我们也可以看到,Android编译环境中使用了out/host/linux-x86/bin/soslim工具
进行STRIP。
有关Android Toolchain的其他一些内容可参考:Android Toolchain与Bionic
Libc
相关文章推荐
- Android编译环境(1)&nbsp;-&nbsp;编译Native&nbsp;…
- android&nbsp;编译环境&nbsp;搭建
- android&nbsp;编译环境&nbsp;搭建
- 在ubuntu&nbsp;下搭建&nbsp;android开发环境
- Ubuntu 10.04环境下载&编译Android-2.2.1 (froyo) 源代码
- Ubuntu 10.04环境下载&编译Android-2.1_r2源代码
- android编译时出现cannot fin…
- Ubuntu上搭建android BSP的开发编译环境 && 设置定时编译任务 && ubuntu从10.04升级到12.04后编译出错
- Ubuntu 10.04环境下载&编译Android-2.2.1 (froyo) 源代码 1/2
- Android系统编译环境搭建—Ubuntu14.04安装&root登录&Chromium root启动&安装配置交叉编译环境
- 用android&nbsp;build&nbsp;system&nbsp;编译自己…
- Ubuntu 10.04环境下载&编译Android-2.2.1
- [原]eclipse 编译c/c++环境搭建问…
- 搭建Android开发环境开启Hello&nbsp;Wor…
- 一个UNIX环境下编译动态brew&nbsp;app的…
- Ubuntu 10.04环境下载&编译Android-2.1_r2源代码
- Android&nbsp;NDK学习之&nbsp;环境搭建-下载…
- Android编译大全&nbsp;(转载)
- Android NDK&&JNI 编译环境的搭建
- Ubuntu&nbsp;10.10&nbsp;64Bit下编译Android&nbsp;…