p_led_opr怎么做到和上述board_demo_led_opr建立联系的？

要让p_led_opr指向board_demo_led_opr结构体变量，需要在代码中进行赋值操作，例如：

struct led_operations board_demo_led_opr = {
    .init = board_demo_led_init,
    .ctl = board_demo_led_ctl,
};

struct led_operations *p_led_opr = &board_demo_led_opr;

这样，p_led_opr指向board_demo_led_opr结构体变量的地址，就可以通过p_led_opr调用对应的LED操作函数了。