Today I have a "burst device". What it can do? You can't figure out!! Actually, it just a reset button on my desk for convenient. It is easy to reset my computer now. When u must reset ur computer more than ten times a day. It will be necessary to have reset button on ur hand.
Surfing on minix news group, and I find it claim it has serial port output in kernel, but actually it is not complete. UART, controller for controlling serial port ,game port and ...I didn;t got fimiliar with it.
Implemetation: I write init_serialport(in kernel/kprintf.c) , it will be called in kernel main function if SERIAL_DEBUG is defined. Then what kputc()(in kernel/kprintf.c) do is to write one char to register.
Thanks to http://www.beyondlogic.org/serial/serial.htm#1