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Drop use of BIOS int 0x14 services in favor of direct port I/O.

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Feedback and testing: Adrian Filipi-Martin <adrian@ubergeeks.com>
This commit is contained in:
Robert Nordier 1998-11-22 07:59:16 +00:00
parent ba924eaf7c
commit 5103ed619b
1 changed files with 48 additions and 37 deletions
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85
sys/boot/i386/libi386/comconsole.c
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@ -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);
}