如何构建在Android上运行的本机(命令行)可执行文件？

Question

我在构建使用本机(JNI)库的Android应用程序(GUI)方面取得了成功.

但是,现在我想创建一个从命令行运行的可执行文件(root权限),并且根本不使用GUI.我该如何构建这样的东西？

Answer 1

从NDK r8d开始,这可以通过更简单的方式解决.

1. 使用以下目录层次结构创建项目:

   project/
       jni/
           Android.mk
           Application.mk
           *.c, *.cpp, *.h, etc.
   

2. 使用以下内容填写Android.mk.最重要的是最后一行.检查NDK doc以获取其他变量的含义.

   LOCAL_PATH := $(call my-dir)
   
   include $(CLEAR_VARS)
   
   LOCAL_MODULE := name-of-your-executable
   LOCAL_SRC_FILES := a.cpp b.cpp c.cpp etc.cpp
   LOCAL_CPPFLAGS := -std=gnu++0x -Wall -fPIE         # whatever g++ flags you like
   LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog -fPIE -pie   # whatever ld flags you like
   
   include $(BUILD_EXECUTABLE)    # <-- Use this to build an executable.
   

3. 转到project/目录,然后输入

   ndk-build
   

   结果将被放入project/libs/<arch>/name-of-your-executable.

Answer 2

http://www.bekatul.info/content/native-c-application-android [破碎(2015年11月9日)]

总结一下这篇文章......

测试代码是:

#include  <stdio.h>//for printf
#include  <stdlib.h>//for exit

int main(int argc, char **argv)
{
        int i = 1;
        i+=2;

        printf("Hello, world (i=%d)!\n", i);

        return 0;
        exit(0);
}

Makefile是:

APP := test
ROOT := /home/dd/android
INSTALL_DIR := /data/tmp
NDK_PLATFORM_VER := 8

ANDROID_NDK_ROOT := $(ROOT)/android-ndk-r5
ANDROID_NDK_HOST := linux-x86
ANDROID_SDK_ROOT := $(ROOT)/android-sdk-linux_86
PREBUILD := $(ANDROID_NDK_ROOT)/toolchains/arm-eabi-4.4.0/prebuilt/$(ANDROID_NDK_HOST)

BIN := $(PREBUILD)/bin/
LIB := $(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/lib
INCLUDE := $(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/include

CC := $(BIN)/arm-eabi-gcc
GDB_CLIENT := $(BIN)/arm-eabi-gdb

LIBCRT := $(LIB)/crtbegin_dynamic.o

LINKER := /system/bin/linker

DEBUG := -g

CFLAGS := $(DEBUG) -fno-short-enums -I$(INCLUDE)
CFLAGS += -Wl,-rpath-link=$(LIB),-dynamic-linker=$(LINKER) -L$(LIB)
CFLAGS += -nostdlib -lc

all: $(APP)

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

install: $(APP)
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(APP) $(INSTALL_DIR)/$(APP) 
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/$(APP)

shell:
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell

run:
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/$(APP)

debug-install:
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILD)/../gdbserver $(INSTALL_DIR)/gdbserver
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/gdbserver

debug-go:
        $(ANDROID_SDK_ROOT)/platform-tools/adb forward tcp:1234: tcp:1234
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/gdbserver :1234 $(INSTALL_DIR)/$(APP)

debug:
        $(GDB_CLIENT) $(APP)

clean:
        @rm -f $(APP).o $(APP)

作者将这些文件存储在他/她的本地Linux计算机上:

/home/dd/android/dev/native/test.c
/home/dd/android/dev/native/Makefile

然后作者编译并测试它:

dd@abil:~/android/dev/native$ make clean; make; make install; make run
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gcc -c  -fno-short-enums -I/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/include test.c -o test.o 
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-g++ -Wl,--entry=main,-dynamic-linker=/system/bin/linker,-rpath-link=/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -L/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -nostdlib -lc -o test test.o
/home/dd/android/android-sdk-linux_86/platform-tools/adb push test /data/tmp/test 
45 KB/s (2545 bytes in 0.054s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/test
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell /data/tmp/test
Hello, world (i=3)!

SDK和NDK使用的是:

source code: /home/dd/android/dev/native
android ndk: /home/dd/android/android-ndk-r5
android sdk: /home/dd/android/android-sdk-linux_86

但是,调试指南是非常好的部分!复制并粘贴......

设置编译以启用调试:

DEBUG = -g
CFLAGS := $(DEBUG) -fno-short-enums -I$(ANDROID_NDK_ROOT)/platforms/android-$(NDK_PLATFORM_VER)/arch-arm/usr/include

将gdbserver文件($(PREBUILD)/../ gdbserver)复制到模拟器,在Makefile中添加目标,使其变得简单:

debug-install:
        $(ANDROID_SDK_ROOT)/platform-tools/adb push $(PREBUILD)/../gdbserver $(INSTALL_DIR)/gdbserver
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell chmod 777 $(INSTALL_DIR)/gdbserver

现在我们将调试@port 1234:

debug-go:
        $(ANDROID_SDK_ROOT)/platform-tools/adb forward tcp:1234: tcp:1234
        $(ANDROID_SDK_ROOT)/platform-tools/adb shell $(INSTALL_DIR)/gdbserver :1234 $(INSTALL_DIR)/$(APP)

然后执行它:

dd@abil:~/android/dev/native$ make clean; make; make install; make debug-install; make debug-go
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gcc -c  -g -fno-short-enums -I/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/include test.c -o test.o 
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-g++ -Wl,--entry=main,-dynamic-linker=/system/bin/linker,-rpath-link=/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -L/home/dd/android/android-ndk-r5/platforms/android-9/arch-arm/usr/lib -nostdlib -lc -o test test.o
/home/dd/android/android-sdk-linux_86/platform-tools/adb push test /data/tmp/test 
71 KB/s (3761 bytes in 0.051s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/test
/home/dd/android/android-sdk-linux_86/platform-tools/adb push /home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/../gdbserver /data/tmp/gdbserver
895 KB/s (118600 bytes in 0.129s)
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell chmod 777 /data/tmp/gdbserver
/home/dd/android/android-sdk-linux_86/platform-tools/adb forward tcp:1234: tcp:1234
/home/dd/android/android-sdk-linux_86/platform-tools/adb shell /data/tmp/gdbserver :1234 /data/tmp/test
Process /data/tmp/test created; pid = 472
Listening on port 1234

现在打开其他控制台并执行调试器:

dd@abil:~/android/dev/native$ make debug
/home/dd/android/android-ndk-r5/toolchains/arm-eabi-4.4.0/prebuilt/linux-x86/bin//arm-eabi-gdb test
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "--host=x86_64-linux-gnu --target=arm-elf-linux"...
(gdb) target remote :1234
Remote debugging using :1234
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
0xb0001000 in ?? ()
(gdb) b main
Breakpoint 1 at 0x82fc: file test.c, line 6.
(gdb) c
Continuing.
Error while mapping shared library sections:
/system/bin/linker: No such file or directory.
Error while mapping shared library sections:
libc.so: Success.

Breakpoint 1, main (argc=33512, argv=0x0) at test.c:6
6               int i = 1;
(gdb) n
7               i+=2;
(gdb) p i
$1 = 1
(gdb) n
9               printf("Hello, world (i=%d)!\n", i);
(gdb) p i
$2 = 3
(gdb) c
Continuing.

Program exited normally.
(gdb) quit

好吧,没关系.而另一个控制台将提供额外的输出,如下所示:

Remote debugging from host 127.0.0.1
gdb: Unable to get location for thread creation breakpoint: requested event is not supported
Hello, world (i=3)!

Child exited with retcode = 0 

Child exited with status 0
GDBserver exiting