Cubietruck---27.android蓝牙分析5_其它

1. packet中的jni,调用协议栈的过程
a.定义
在./hardware/libhardware/include/hardware/bluetooth.h中

#define BT_HARDWARE_MODULE_ID "bluetooth"
#define BT_STACK_MODULE_ID "bluetooth"

b.jni中
在./packages/apps/Bluetooth/jni/com_android_bluetooth_btservice_AdapterService.cp中

static void classInitNative(JNIEnv* env, jclass clazz) {
    const char *id = (strcmp(value, "1")? BT_STACK_MODULE_ID : BT_STACK_TEST_MODULE_ID);
    hw_get_module(id, (hw_module_t const**)&module);   //获取动态库libbluedroid.so的入口
    hw_device_t* abstraction;
    module->methods->open(module, id, &abstraction);    //调用libbluedroid.so的open函数
    bluetooth_module_t* btStack = (bluetooth_module_t *)abstraction;
    sBluetoothInterface = btStack->get_bluetooth_interface();
}

c. 协议栈中
在./external/bluetooth/bluedroid/btif/src/bluetooth.c中

static struct hw_module_methods_t bt_stack_module_methods = {
    .open = open_bluetooth_stack,
};

struct hw_module_t HAL_MODULE_INFO_SYM = {
    .tag = HARDWARE_MODULE_TAG,
    .version_major = 1,
    .version_minor = 0,
    .id = BT_HARDWARE_MODULE_ID,    //通过这个id找到对应的库
    .name = "Bluetooth Stack",
    .author = "The Android Open Source Project",
    .methods = &bt_stack_module_methods
};

c.1 jni调用协议栈的open函数
module->methods->open(module, id, &abstraction);    //调用libbluedroid.so的open函数

static int open_bluetooth_stack (const struct hw_module_t* module, char const* name,
struct hw_device_t** abstraction)
{
    bluetooth_device_t *stack = malloc(sizeof(bluetooth_device_t) );
    memset(stack, 0, sizeof(bluetooth_device_t) );
    stack->common.tag = HARDWARE_DEVICE_TAG;
    stack->common.version = 0;
    stack->common.module = (struct hw_module_t*)module;
    stack->common.close = close_bluetooth_stack;
    stack->get_bluetooth_interface = bluetooth__get_bluetooth_interface;
    *abstraction = (struct hw_device_t*)stack;
    return 0;
}

c.2 jni调用协议栈的get_bluetooth_interface函数
bluetooth_module_t* btStack = (bluetooth_module_t *)abstraction;
 sBluetoothInterface = btStack->get_bluetooth_interface();
在./external/bluetooth/bluedroid/btif/src/bluetooth.c中

const bt_interface_t* bluetooth__get_bluetooth_interface ()
{
    return &bluetoothInterface;
}

返回了 Bluetooth DM interface的结构体 这样jni就可以调用蓝牙的打开，关闭，discovery的接口了。