Android P BT MAC 地址通过factory节点读取

获取蓝牙mac地址的逻辑在bluetooth_address.cpp
vendor/qcom/proprietary/bluetooth/hidl_transport/bt/1.0/default/)

默认是有六种读取方式
// Get addr from vendor location
// Get local bdaddr storage path from a system property.
// No BDADDR found in the file. Look for BDA in a factory property.
// Check if address is stored @ Modem NV
// No factory BDADDR found. Look for a previously stored BDA.
/* Generate new BDA if necessary */
由于项目把moderm去掉了 所以原生从nv447写入的mac地址后，由qmi方式从moderm读取的方式不生效了。决定从factory节点读取
下面是实现方式
//从factory节点读出来操作

bool BluetoothAddress::GetFactoryBtAddress( char * btAddr) {
    const int bt_index = 806;//从806写入 写12位
    const int bt_length =13;
    int fd = -1;
    char bt_buf[13] = {0};
    memset( btAddr, 0, 24);
        //节点位置
    fd = open("/dev/block/bootdevice/by-name/factory", O_RDONLY);
    if (fd == -1){
                //如果没有SELINUX权限  读取不成功
        ALOGE("open factory partiton, read bt_buf failed");
        return false;
    } else {
        int i = 0;
        lseek(fd, bt_index,  SEEK_SET);
        read(fd, bt_buf, bt_length);
                bt_buf[bt_length - 1] = '\0';
        ALOGE("read factory bt 806 address bt_buf value(%s)", bt_buf);
        if(strlen(bt_buf) == 0){
            ALOGE("read factory bt 806 address bt_buf value is null ");
            return false;
        }
        for( i = 0; i < bt_length; i++){
            btAddr[i] = bt_buf[i];
        }
        ALOGE("read factory bt address ,  btAddr(%s) ", btAddr);
        close(fd);
        return true;
    }
    return false;
}

下面是调用方法

    if (GetFactoryBtAddress(property)) {
        ALOGE("read factory,  GetFactoryBtAddress property(%s) ", property);
        using namespace std;
        string strs;
        strs=property;
        string btStrs;
        for(int a = 0; a <= 5; a++){
            string x = strs.substr(2*a,2);
            btStrs.append(x);
              if(5 != a){
                btStrs.append(":");
              }
        }
        ALOGE("read factory, btStrs.c_str()(%s) ", btStrs.c_str());
        if (StringToBytes(btStrs.c_str(), local_addr)){
            ALOGE("read factory, local_addr(%s) ", local_addr);
            valid_bda = true;
            le2bd(local_addr);
        }
      }

不要忘记在.h文件声明

  static bool GetFactoryBtAddress(char *btAddr);

之后还要解决SELINUX权限的问题 缺少什么权限加什么权限