ok6410 android driver(5)

　　Test the android driver by JNI (Java Native Interface),

　　In the third article, we know how to compiler the moduler for localhost, ok6410 and goldfish platform.

http://www.cnblogs.com/plinx/p/3209500.html

　　But we didn't try to test the driver using by C/C++ program on ok6410 and goldfish.

　　Android was changing from linux, so there must remain some fetures linux working.

　　If we want to test a driver using C/C++ program, we should get ready for the following conditions :

　　(1) Goldfish emulator/Ok6410/Phone must got the permission to "root".

　　(2) The exec file compiled by the cross compiler.

　　It's easy to go on within these limits, we just need to compile the C/C++ program in the android source configured by "Android.mk".

　　

　　Here is the Android.mk :

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

# files to compiler
LOCAL_SRC_FILES := ftest.c

# obj name - the output execute file name
LOCAL_MODULE := ftest

LOCAL_MODULE_TAGS := optional

include $(BUILD_EXECUTABLE)

　　And the ftest.c is :

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[])
{
    int testdev;
    int ret;
    int num = 0;
    unsigned char buf[4];

    testdev = open("/dev/wordcount2", O_RDWR);

    if(testdev == -1) {
        printf("Can not open file.\n");
        return 0;
    }

    if(argc > 1) {
        printf("Strings : %s.\n", argv[1]);
        write(testdev, argv[1], strlen(argv[1]));
    }

    read(testdev, buf, 4);

    num =     ((int)buf[0]) << 24 | \
        ((int)buf[1]) << 16 | \
        ((int)buf[2]) << 8  | \
        ((int)buf[3]);

    printf("Word Byte : 0x%d%d%d%dH\n", buf[0], buf[1], buf[2], buf[3]);
    printf("word count: %d\n", num);

    close(testdev);
    return 0;
}

　　now, we should mkdir in the source code :

$ pwd
~/Android/source_code/development/ndk/wordcount
$ ls
Android.mk  ftest.c

　　then return to the root directory :

$ cd ~/Android/source_code/
$ source build/envsetup.sh
$ mmm development/ndk/wordcount
...
Install: out/target/product/generic/system/bin/ftest
...

　　Then we just need to push the file to emulator and test it.