Four compilation methods of Helloworld in Android Native C

Document directory

• 1. Compile helloworld. c Android. mk

1. Compile helloworld. c Android. mk

[Root @ fontlose jni] # cat hello. c

[Cpp]
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1. # Include <stdio. h>
2. Int main ()
3. {
4. Printf ("Hello World! \ N ");
5. Return 0;
7. }

[Root @ fontlose jni] # cat Android. mk

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1. LOCAL_PATH: = $ (call my-dir)
2. Include $ (CLEAR_VARS)
3. LOCAL_SRC_FILES: = hello. c
4. LOCAL_MODULE: = helloworld
5. LOCAL_MODULE_TAGS: = optional
6. Include $ (BUILD_EXECUTABLE)

Ii. Compile 1) Use NDK r5

Directory structure-hello
── Jni
── Android. mk

── Hello. c

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1. [Root @ fontlose nativity] # cd hello
2. [Root @ fontlose hello] # export NDK_PROJECT_PATH = 'pwd'
3. [Root @ fontlose hello] # ndk-build
4. Install: helloworld => libs/armeabi/helloworld
6. [Root @ fontlose hello] # adb push libs/armeabi/helloworld/data
7. 44 KB/s (2176 bytes in 0.047 s)
9. [Root @ fontlose hello] # adb shell
10. /# Cd/data
11. /Data # ls-l
12. -Rwxrwxrwx root 2176 2011-08-07 0:01 helloworld
13. /Data #./helloworld
14. Hello World!

2) use the general toolchain

Under the hello. c directory[Plain]
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1. [Root @ fontlose jni] # arm-none-linux-gnueabi-gcc-static hello. c-o helloworld
2. [Root @ fontlose jni] # adb push helloworld/data
3. 1718 KB/s (581219 bytes in 0.330 s)
4. [Root @ fontlose jni] # adb shell
5. /# Cd/data
6. /Data # ls-l
7. -Rwxrwxrwx Root 581219 helloworld
8. /Data #./helloworld
9. 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) compile in the source code Environment

1. Create the hello directory under the development Directory of the source code.[Plain]
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1. [Root @ fontlose Android-2.3] # mkdir $ android_src/development/Hello

2. Copy helloworld. c Android. mk to the hello directory.
3. [root @ fontlose Android-2.3] #. build/envsetup. sh

4. [root @ fontlose Android-2.3] # mmm development/hello/

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1. ========================================================== ====
2. Platform_version_codename = REL
3. Platform_version = 2.3.2
4. Target_product = generic
5. Target_build_variant = ENG
6. Target_simulator =
7. Target_build_type = release
8. TARGET_BUILD_APPS =
9. TARGET_ARCH = arm
10. HOST_ARCH = x86
11. HOST_ OS = linux
12. HOST_BUILD_TYPE = release
13. BUILD_ID = GRH78C
14. ========================================================== ====
15. Make: Enter the directory "/opt/FriendlyARM/mini6410/android/Android-2.3"
16. Target thumb C: helloworld <= development/hello. c
17. Target Executable: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)
18. Target Non-prelinked: helloworld (out/target/product/generic/symbols/system/bin/helloworld)
19. Target Strip: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)
20. Install: out/target/product/generic/system/bin/helloworld
21. Make: Leave the directory "/opt/FriendlyARM/mini6410/android/Android-2.3"

5. After compilation is completed, the execution file is in out/target/product/generic/symbols/system/bin/helloworld.
Download To device[Plain]
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1. [Root @ fontlose Android-2.3] # adb push out/target/product/generic/symbols/system/bin/helloworld/data
2. 135 KB/s (7608 bytes in 0.054 s)
3. [Root @ fontlose Android-2.3] # adb shell
4. /# Cd/data
5. /Data # ls-l
6. -Rwxrwxrwx Root 7608 helloworld
7. /Data #./helloworld
8. Hello world!

4) use the Toolchain provided by the source code

Before that, we need to clean the helloworld module in the previous step:[Plain]
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1. [Root @ fontlose Android-2.3] # Make clean-helloworld

Use the showcommands option to re-compile helloworld and view the specific commands. The output command line shows that, the cross-compilation tool chain used by the Android compiling environment is prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-gcc.[Plain]
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1. [Root @ fontlose Android-2.3] # Make helloworld showcommands

Use the compilation command output above to simplify the manual compilation of the helloworld program. First, manually delete the helloworld program compiled last time:[Plain]
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1. [Root @ fontlose Android-2.3] # rm out/target/product/generic/system/bin/helloworld

Gcc compilation to generate the target file[Plain]
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1. [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/ril/ include-I dalvik/libnativehelper/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/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-d1_arm_arch_5 _-region _-d1_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. c

Generate an executable file:[Plain]
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1. [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

STRIP using out/host/linux-x86/bin/soslim Tool[Plain]
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1. [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

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1. [Root @ fontlose Android-2.3] # adb push out/target/product/generic/symbols/system/bin/helloworld/data
2. 145 KB/s (7608 bytes in 0.051 s)
3. [Root @ fontlose Android-2.3] # adb shell
4. /# Cd/data/
5. /Data # ls-l
6. -Rwxrwxrwx root 7608 helloworld
7. /Data #./helloworld
8. Hello World!

Android does not use glibc as the C library, but uses the Bionic Libc developed by Google. it is feasible to use the general Toolchain to compile and transplant the Android Linux kernel, because the kernel does not need the C library, however, when developing Android applications, other Toolchain-compiled applications can only run in static compiling mode, and the execution files compiled in static mode are relatively large.