| Current Path : /usr/src/sys/boot/i386/boot2/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/sys/boot/i386/boot2/sio.S |
/* * Copyright (c) 1998 Robert Nordier * All rights reserved. * * Redistribution and use in source and binary forms are freely * permitted provided that the above copyright notice and this * paragraph and the following disclaimer are duplicated in all * such forms. * * This software is provided "AS IS" and without any express or * implied warranties, including, without limitation, the implied * warranties of merchantability and fitness for a particular * purpose. * * $FreeBSD: release/9.1.0/sys/boot/i386/boot2/sio.S 220337 2011-04-04 18:23:55Z rdivacky $ */ .set SIO_PRT,SIOPRT # Base port .set SIO_FMT,SIOFMT # 8N1 .globl sio_init .globl sio_flush .globl sio_putc .globl sio_getc .globl sio_ischar /* void sio_init(int div) */ sio_init: pushl %eax movw $SIO_PRT+0x3,%dx # Data format reg movb $SIO_FMT|0x80,%al # Set format outb %al,(%dx) # and DLAB subb $0x3,%dl # Divisor latch reg popl %eax outw %ax,(%dx) # BPS movw $SIO_PRT+0x3,%dx # Data format reg movb $SIO_FMT,%al # Clear outb %al,(%dx) # DLAB incl %edx # Modem control reg movb $0x3,%al # Set RTS, outb %al,(%dx) # DTR incl %edx # Line status reg call sio_flush ret /* void sio_flush(void) */ sio_flush.0: call sio_getc.1 # Get character sio_flush: call sio_ischar # Check for character jnz sio_flush.0 # Till none ret # To caller /* void sio_putc(int c) */ sio_putc: pushl %eax movw $SIO_PRT+0x5,%dx # Line status reg xor %ecx,%ecx # Timeout movb $0x40,%ch # counter sio_putc.1: inb (%dx),%al # Transmitter testb $0x20,%al # buffer empty? loopz sio_putc.1 # No jz sio_putc.2 # If timeout popl %eax # Get the character subb $0x5,%dl # Transmitter hold reg outb %al,(%dx) # Write character sio_putc.2: ret # To caller /* int sio_getc(void) */ sio_getc: call sio_ischar # Character available? jz sio_getc # No sio_getc.1: subb $0x5,%dl # Receiver buffer reg inb (%dx),%al # Read character ret # To caller /* int sio_ischar(void) */ sio_ischar: movw $SIO_PRT+0x5,%dx # Line status register xorl %eax,%eax # Zero inb (%dx),%al # Received data andb $0x1,%al # ready? ret # To caller