2 * Copyright (c) 1998 Michael Smith (msmith@freebsd.org)
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * $FreeBSD: src/sys/boot/i386/libi386/comconsole.c,v 1.7.2.1 2000/12/28 13:12:40 ps Exp $
29 #include <bootstrap.h>
30 #include <machine/cpufunc.h>
33 /* selected defines from ns16550.h */
34 #define com_data 0 /* data register (R/W) */
35 #define com_dlbl 0 /* divisor latch low (W) */
36 #define com_dlbh 1 /* divisor latch high (W) */
37 #define com_ier 1 /* interrupt enable (W) */
38 #define com_iir 2 /* interrupt identification (R) */
39 #define com_fifo 2 /* FIFO control (W) */
40 #define com_lctl 3 /* line control register (R/W) */
41 #define com_cfcr 3 /* line control register (R/W) */
42 #define com_mcr 4 /* modem control register (R/W) */
43 #define com_lsr 5 /* line status register (R/W) */
44 #define com_msr 6 /* modem status register (R/W) */
46 /* selected defines from sioreg.h */
47 #define CFCR_DLAB 0x80
50 #define LSR_TXRDY 0x20
51 #define LSR_RXRDY 0x01
53 #define COMC_FMT 0x3 /* 8N1 */
54 #define COMC_TXWAIT 0x40000 /* transmit timeout */
55 #define COMC_BPS(x) (115200 / (x)) /* speed to DLAB divisor */
64 static void comc_probe(struct console *cp);
65 static int comc_init(int arg);
66 static void comc_putchar(int c);
67 static int comc_getchar(void);
68 static int comc_ischar(void);
70 static int comc_started;
72 struct console comconsole = {
84 comc_probe(struct console *cp)
86 /* XXX check the BIOS equipment list? */
87 cp->c_flags |= (C_PRESENTIN | C_PRESENTOUT);
93 if (comc_started && arg == 0)
97 outb(COMPORT + com_cfcr, CFCR_DLAB | COMC_FMT);
98 outb(COMPORT + com_dlbl, COMC_BPS(COMSPEED) & 0xff);
99 outb(COMPORT + com_dlbh, COMC_BPS(COMSPEED) >> 8);
100 outb(COMPORT + com_cfcr, COMC_FMT);
101 outb(COMPORT + com_mcr, MCR_RTS | MCR_DTR);
104 inb(COMPORT + com_data);
105 while (inb(COMPORT + com_lsr) & LSR_RXRDY);
115 for (wait = COMC_TXWAIT; wait > 0; wait--)
116 if (inb(COMPORT + com_lsr) & LSR_TXRDY) {
117 outb(COMPORT + com_data, (u_char)c);
125 return(comc_ischar() ? inb(COMPORT + com_data) : -1);
131 return(inb(COMPORT + com_lsr) & LSR_RXRDY);