/* This function will write a character to serial without interrupt enable mode */
void rt_serial_putc(const char c)
/* This function will write a character to serial without interrupt enable mode */
void rt_serial_putc(const char c)
{
    int val;
    while(1)
    {
           if ((val = inb(COM1+COMSTATUS)) & THRE)
            break;
    }
    outb(COM1+COMWRITE, c&0xff);
}