Question

怎么使用Android源码编译c模块生成可执行文件

使用的是海思的SDK，这个应该跟Android的编译环境差不多吧。各位大侠 我的问题是这样的写了个helloworld的测试程序，是可以编译成可执行程序然后在机器上运行打印出来的。但是呢，在编译模块的时候遇到问题了。按照之前的方式，在development下创建一个文件夹moudle，然后把所有需要的.c .h .so文件都搬了过来，写了个Android.mk，但是呢 在里面添加一句LOCAL_SHARED_LIBRARIES += libcrypto libcurl 之后就报make: *** No rule to make target out/target/product/Hi3798MV100/obj/SHARED_LIBRARIES/libcurl_intermediates/export_includes', needed byout/target/product/Hi3798MV100/obj/SHARED_LIBRARIES/wifiAudit_intermediates/import_includes'. Stop.make: Leaving directory `/home/zhanglf/android/customer/60/cn/software/his60'这样的错误 是为什么呢请赐教，qq 309858937
byout/target/product/Hi3798MV100/obj/SHARED_LIBRARIES/wifiAudit_intermediates/import_includes'. Stop.
这个错误是为什么呢。 helloworld的 测试程序我已经调试通过了，模块需要一些 库我在Android.mk中添加了
39 include $(CLEAR_VARS)
40 LOCAL_MODULE := libz
41 LOCAL_SRC_FILES := $(LOCAL_PATH)/static_include/libz.so.1.2.8
42 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
43 include $(PREBUILT_STATIC_LIBRARY)

Answer 1

1. 在./development目录下创建一目录 如：myhello
2. 进入hello目录，在其下编写自己的.c文件,如: myhello.c
#include <stdio.h>
int main()
{
printf("hello world\n");
exit(0);
//return 0;
}
3. 在hello目录中，编写Android.mk, 内容如下：
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := myhelloworld
LOCAL_SRC_FILES := myhello.c
LOCAL_MODULE_TAGS := optional
include $(BUILD_EXECUTABLE)
4. 回到Android源代码顶层目录，进行编译，make myhelloworld
5. 生成的可执行文件位于:out/target/product/lotus/system/bin/ 目录下
6. adb push 到手机 /data 目录下,然后进入adb shell,到data目录下,执行./myhelloworld 皆可

手动编译连接【arm-eabi-gcc 的目录随andorid的版本而有变化，还有就是需要链接的文件如果比较多时，需要很多-l 就很麻烦了】
7、编译成目标文件：
#$(yourAndroid)/prebuilt/linux-x86/toolchain/[arm-eabi-4.2.1]/bin/arm-eabi-gcc -I bionic/libc/arch-arm/include/ -I bionic/libc/include -I bionic/libc/kernel/common -I bionic/libc/kernel/arch-arm -g -c helloworld.c -o hello.o
8、生成可执行代码：
#$(yourAndroid)/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 helloworld -Lout/target/product/[generic]/obj/lib -Wl,-rpath-link=out/target/product/[generic]/obj/lib -lc hello.o -entry=main

其中[ ]中部分根据实际情况修改

**************************************************
实验：
1. 建目录(my Android)/development/test， 在该目录下新建 Android.mk和fb_test.c文件

2. Android.mk文件

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := myfbtest
LOCAL_SRC_FILES := fb_test.c
LOCAL_MODULE_TAGS := optional
include $(BUILD_EXECUTABLE)

3. 以下为fb_test.c
#include <fcntl.h>
#include <linux/fb.h>
#include <sys/mman.h>
#include <linux/kd.h>

#include <stdio.h>

#define FBBIT_PER_PIXEL 32
#define FBBIT_PIXEL_IMAGE 16
#define PIXELS_WIDTH_BYTE 4
#define BYTE_PER_PIXEL 3
#define FB_GRAPHICS_PATH "/dev/graphics/fb0"
#define DEV_TTY0_PATH "/dev/tty0"

#define DISPLAY_ERROR -1
#define DISPLAY_SUCCESS 0

#define GET_BATTERYCAPACITY_ERR -1

#define MAX_STR 255

static struct {
int fd;
void *pixels;
struct fb_fix_screeninfo fixed;
struct fb_var_screeninfo var;
int align_xres;
} fb;

int getBatteryCapacity(void)
{
FILE *in;
char tmpStr[MAX_STR + 1];
char capfile[] = "/sys/class/power_supply/battery/capacity";

if (capfile == NULL)
return GET_BATTERYCAPACITY_ERR;

in = fopen(capfile, "rt");
if (in == NULL)
return GET_BATTERYCAPACITY_ERR;

if (fgets(tmpStr, MAX_STR, in) == NULL) {
printf("Failed to read battery capacity!\n");
fclose(in);
return GET_BATTERYCAPACITY_ERR;

}

printf("Battery capacity(ascii): %s\n", tmpStr);
fclose(in);

return 0;//atoi(tmpStr);
}

static int vt_set_graphicsmode(int graphics)
{
int fd, r;
fd = open(DEV_TTY0_PATH, O_RDWR | O_SYNC);
if (fd < 0)
return DISPLAY_ERROR;
r = ioctl(fd, KDSETMODE, graphics);
close(fd);
return r;
}

int display_init(void)
{
fb.fd = open(FB_GRAPHICS_PATH, O_RDWR);
if (fb.fd < 0)
return DISPLAY_ERROR;

if (ioctl(fb.fd, FBIOGET_FSCREENINFO, &fb.fixed) < 0)
return DISPLAY_ERROR;
if (ioctl(fb.fd, FBIOGET_VSCREENINFO, &fb.var) < 0)
return DISPLAY_ERROR;
fb.align_xres = fb.fixed.line_length /
(fb.var.bits_per_pixel >> BYTE_PER_PIXEL);

fb.pixels = mmap(0, fb.fixed.line_length * fb.var.yres_virtual,
PROT_READ | PROT_WRITE, MAP_SHARED, fb.fd, 0);
if (fb.pixels == MAP_FAILED)
return DISPLAY_ERROR;

vt_set_graphicsmode(KD_GRAPHICS);

memset(fb.pixels, 0, fb.fixed.line_length * fb.var.yres_virtual);
//display_update(fb.pixels, fb.align_xres, fb.var.yres);
fb.var.activate = FB_ACTIVATE_FORCE;
ioctl(fb.fd, FBIOPUT_VSCREENINFO, &fb.var);

printf("display_init ok\n");

return DISPLAY_SUCCESS;
}

void display_on(void)
{
ioctl(fb.fd, FBIOBLANK, FB_BLANK_UNBLANK);
}

void display_off(void)
{
ioctl(fb.fd, FBIOBLANK, FB_BLANK_POWERDOWN);
}

int main()
{
display_init();
display_off();//关显示屏

getBatteryCapacity();
sleep(5);

display_on();//开显示屏

return 0;
}

追问

感谢您的回答，但是我想请问一下
添加一句LOCAL_SHARED_LIBRARIES += libcrypto libcurl 之后就报
make: *** No rule to make target out/target/product/Hi3798MV100/obj/SHARED_LIBRARIES/libcurl_intermediates/export_includes', needed