主要介绍一下从bluetooth service 到 bluetooth stack 到 hci layer 到 vendor层 bluetooth enable 的程序流程，有不对之处，敬请指正。
程序流程图：
一. ClassInitNative 1. 加载 bluetooth.default.so static void classInitNative(JNIEnv* env, jclass clazz) { int err; hw_module_t* module; ...... err = hw_get_module(id, (hw_module_t const**)&module); // 加载/system/lib/hw/或者/system/lib64/hw 目录下bluetooth.default.so if (err == 0) { hw_device_t* abstraction; err = module->methods->open(module, id, &abstraction); if (err == 0) { bluetooth_module_t* btStack = (bluetooth_module_t *)abstraction; sBluetoothInterface = btStack->get_bluetooth_interface(); } else { ALOGE("Error while opening Bluetooth library"); } } else { ALOGE("No Bluetooth Library found"); } }
2. 设置bluetooth interface
static int open_bluetooth_stack(const struct hw_module_t *module, UNUSED_ATTR char const *name, struct hw_device_t **abstraction) { static bluetooth_device_t device = { .common = { .tag = HARDWARE_DEVICE_TAG, .version = 0, .close = close_bluetooth_stack, }, .get_bluetooth_interface = bluetooth__get_bluetooth_interface }; device.common.module = (struct hw_module_t *)module; *abstraction = (struct hw_device_t *)&device; return 0; } 二. initNative 1. init stack static void init_stack(void) { semaphore_t *semaphore = semaphore_new(0); thread_post(management_thread, event_init_stack, semaphore); semaphore_wait(semaphore); semaphore_free(semaphore); } 2. 获取hal层，vendor层interface 获取read_data, transmit_data接口，实现hci层和vendor device的通信 const hci_t *hci_layer_get_interface() { buffer_allocator = buffer_allocator_get_interface(); hal = hci_hal_get_interface(); btsnoop = btsnoop_get_interface(); hci_inject = hci_inject_get_interface(); packet_fragmenter = packet_fragmenter_get_interface(); vendor = vendor_get_interface(); low_power_manager = low_power_manager_get_interface(); init_layer_interface(); return &interface; } 三. enableNative 1. 加载libbt-vendor.so， 并初始化 static bool vendor_open( const uint8_t *local_bdaddr, const hci_t *hci_interface) { assert(lib_handle == NULL); hci = hci_interface; lib_handle = dlopen(VENDOR_LIBRARY_NAME, RTLD_NOW); ...... lib_interface = (bt_vendor_interface_t *)dlsym(lib_handle, VENDOR_LIBRARY_SYMBOL_NAME); ...... int status = lib_interface->init(&lib_callbacks, (unsigned char *)local_bdaddr); } ...... }2. hci layer发送VENDOR_CHIP_POWER_CONTROL 消息
vendor->send_command(VENDOR_CHIP_POWER_CONTROL, &power_state);
power up bluetooth device
3. hal_open， 打开/dev/smd3, smd2的设备节点
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opcode defined in:
system/bt/stack/include/hcidefs.h
