Solution:

The following are relative sub-routines about LED: led_init() { outport(0xff76,inport(0xff76) | 0x0400); /* output mode */ outport(0xff78,inport(0xff78) & 0xfbff); /* 10 */ } led_on() { outport(0xff7a,inport(0xff7a) | 0x0400); /* LED = 1 */ } led_off() { outport(0xff7a,inport(0xff7a) & 0xfbff); /* LED = 0 */ }