From 2b7d69a8df339184f0c209580795574e9198545e Mon Sep 17 00:00:00 2001
From: rnordier <rnordier@FreeBSD.org>
Date: Sun, 22 Nov 1998 07:59:16 +0000
Subject: Drop use of BIOS int 0x14 services in favor of direct port I/O.

Feedback and testing: Adrian Filipi-Martin <adrian@ubergeeks.com>
---
 sys/boot/i386/libi386/comconsole.c | 85 +++++++++++++++++++++-----------------
 1 file changed, 48 insertions(+), 37 deletions(-)

(limited to 'sys/boot/i386/libi386/comconsole.c')

diff --git a/sys/boot/i386/libi386/comconsole.c b/sys/boot/i386/libi386/comconsole.c
index 261e909..b530eeb 100644
--- a/sys/boot/i386/libi386/comconsole.c
+++ b/sys/boot/i386/libi386/comconsole.c
@@ -22,16 +22,41 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * 	From Id: probe_keyboard.c,v 1.13 1997/06/09 05:10:55 bde Exp
- *
- *	$Id: comconsole.c,v 1.3 1998/10/02 16:32:45 msmith Exp $
+ *	$Id: comconsole.c,v 1.4 1998/10/11 10:05:13 peter Exp $
  */
 
 #include <stand.h>
 #include <bootstrap.h>
-#include <btxv86.h>
+#include <machine/cpufunc.h>
 #include "libi386.h"
 
+/* selected defines from ns16550.h */
+#define	com_data	0	/* data register (R/W) */
+#define	com_dlbl	0	/* divisor latch low (W) */
+#define	com_dlbh	1	/* divisor latch high (W) */
+#define	com_ier		1	/* interrupt enable (W) */
+#define	com_iir		2	/* interrupt identification (R) */
+#define	com_fifo	2	/* FIFO control (W) */
+#define	com_lctl	3	/* line control register (R/W) */
+#define	com_cfcr	3	/* line control register (R/W) */
+#define	com_mcr		4	/* modem control register (R/W) */
+#define	com_lsr		5	/* line status register (R/W) */
+#define	com_msr		6	/* modem status register (R/W) */
+
+/* selected defines from sioreg.h */
+#define	CFCR_DLAB	0x80
+#define	MCR_RTS		0x02
+#define	MCR_DTR		0x01
+#define	LSR_TXRDY	0x20
+#define	LSR_RXRDY	0x01
+
+#define COMC_FMT	0x3		/* 8N1 */
+#define COMC_TXWAIT	0x40000		/* transmit timeout */
+#define COMC_BPS(x)	(115200 / (x))	/* speed to DLAB divisor */
+
+#define COMPORT		0x3f8
+#define COMSPEED	9600
+
 static void	comc_probe(struct console *cp);
 static int	comc_init(int arg);
 static void	comc_putchar(int c);
@@ -42,7 +67,7 @@ static int	comc_started;
 
 struct console comconsole = {
     "comconsole",
-    "BIOS serial port",
+    "serial port",
     0,
     comc_probe,
     comc_init,
@@ -51,8 +76,6 @@ struct console comconsole = {
     comc_ischar
 };
 
-#define BIOS_COMPORT	0
-
 static void
 comc_probe(struct console *cp)
 {
@@ -63,19 +86,19 @@ comc_probe(struct console *cp)
 static int
 comc_init(int arg)
 {
-    int		i;
-
     if (comc_started && arg == 0)
 	return 0;
     comc_started = 1;
-    v86.ctl = 0;
-    v86.addr = 0x14;
-    v86.eax = 0xe3;		/* 9600N81 */
-    v86.edx = BIOS_COMPORT;	/* XXX take as arg, or use env var? */
-    v86int();
 
-    for(i = 0; i < 10 && comc_ischar(); i++)
-        (void)comc_getchar();
+    outb(COMPORT + com_cfcr, CFCR_DLAB | COMC_FMT);
+    outb(COMPORT + com_dlbl, COMC_BPS(COMSPEED) & 0xff);
+    outb(COMPORT + com_dlbh, COMC_BPS(COMSPEED) >> 8);
+    outb(COMPORT + com_cfcr, COMC_FMT);
+    outb(COMPORT + com_mcr, MCR_RTS | MCR_DTR);
+
+    do
+        inb(COMPORT + com_data);
+    while (inb(COMPORT + com_lsr) & LSR_RXRDY);
 
     return(0);
 }
@@ -83,35 +106,23 @@ comc_init(int arg)
 static void
 comc_putchar(int c)
 {
-    v86.ctl = 0;
-    v86.addr = 0x14;
-    v86.eax = 0x100 | c;	/* Function 1 = write */
-    v86.edx = BIOS_COMPORT;	/* XXX take as arg, or use env var? */
-    v86int();
+    int wait;
+
+    for (wait = COMC_TXWAIT; wait > 0; wait--)
+        if (inb(COMPORT + com_lsr) & LSR_TXRDY) {
+	    outb(COMPORT + com_data, c);
+	    break;
+	}
 }
 
 static int
 comc_getchar(void)
 {
-    if (comc_ischar()) {
-	v86.ctl = 0;
-	v86.addr = 0x14;
-	v86.eax = 0x200;	/* Function 2 = read */
-	v86.edx = BIOS_COMPORT;	/* XXX take as arg, or use env var? */
-	v86int();
-	return(v86.eax & 0xff);
-    } else {
-	return(-1);
-    }
+    return(comc_ischar() ? inb(COMPORT + com_data) : -1);
 }
 
 static int
 comc_ischar(void)
 {
-    v86.ctl = 0;
-    v86.addr = 0x14;
-    v86.eax = 0x300;		/* Function 3 = status */
-    v86.edx = BIOS_COMPORT;	/* XXX take as arg, or use env var? */
-    v86int();
-    return(v86.eax & 0x100);	/* AH bit 1 is "receive data ready" */
+    return(inb(COMPORT + com_lsr) & LSR_RXRDY);
 }
-- 
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