cons.c

著名的AT&T UNIX v6 源码

/*
 *   KL/DL-11 driver
 */
#include "../h/param.h"
#include "../h/conf.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/tty.h"
#include "../h/systm.h"
#include "../h/cons.h"
#include "../h/mtpr.h"

#define	NL1	000400
#define	NL2	001000
#define	CR2	020000
#define	FF1	040000
#define	TAB1	002000

struct	tty cons;
int	consstart();
int	ttrstrt();
char	partab[];

consopen(dev, flag)
dev_t dev;
{
	register struct device *addr;
	register struct tty *tp;
	register d;

	tp = &cons;
	tp->t_oproc = consstart;
	tp->t_iproc = NULL;
	if ((tp->t_state&ISOPEN) == 0) {
		tp->t_state = ISOPEN|CARR_ON;
		tp->t_flags = EVENP|ECHO|XTABS|CRMOD;
		tp->t_erase = CERASE;
		tp->t_kill = CKILL;
	}
	mtpr(RXCS, mfpr(RXCS)|RXCS_IE);
	mtpr(TXCS, mfpr(TXCS)|TXCS_IE);
	ttyopen(dev, tp);
}

consclose(dev)
dev_t dev;
{
	register struct tty *tp;

	tp = &cons;
	wflushtty(tp);
	tp->t_state = 0;
}

consread(dev)
dev_t dev;
{
	ttread(&cons);
}

conswrite(dev)
dev_t dev;
{
	ttwrite(&cons);
}

consxint(dev)
dev_t dev;
{
	register struct tty *tp;

	tp = &cons;
	ttstart(tp);
	if (tp->t_outq.c_cc == 0 || tp->t_outq.c_cc == TTLOWAT)
		wakeup((caddr_t)&tp->t_outq);
}

consrint(dev)
dev_t dev;
{
	register int c;
	register struct device *addr;
	register struct tty *tp;

	c = mfpr(RXDB);
	ttyinput(c, &cons);
}

consioctl(dev,cmd,addr,flag)
dev_t dev;
caddr_t addr;
{
	register struct tty *tp;
 
	tp = &cons;
	if (ttioccom(cmd,tp,addr,dev) ==0)
		u.u_error = ENOTTY;
}

consstart(tp)
register struct tty *tp;
{
	register c;
	register struct device *addr;

	if( (mfpr(TXCS)&TXCS_RDY) == 0)
		return;
	if ((c=getc(&tp->t_outq)) >= 0) {
		if (tp->t_flags&RAW)
			mtpr(TXDB, c&0xff);
		else if (c<=0177)
			mtpr(TXDB, (c | (partab[c]&0200))&0xff);
		else {
			timeout(ttrstrt, (caddr_t)tp, (c&0177));
			tp->t_state |= TIMEOUT;
		}
	}
}

char	*msgbufp = msgbuf;	/* Next saved printf character */
/*
 * Print a character on console.
 * Attempts to save and restore device
 * status.
 * If the switches are 0, all
 * printing is inhibited.
 *
 * Whether or not printing is inhibited,
 * the last MSGBUFS characters
 * are saved in msgbuf for inspection later.
 */
putchar(c)
register c;
{
	register s, timo;

	if (c != '\0' && c != '\r' && c != 0177) {
		*msgbufp++ = c;
		if(msgbufp >= &msgbuf[MSGBUFS])
			msgbufp = msgbuf;
	}
	timo = 30000;
	/*
	 * Try waiting for the console tty to come ready,
	 * otherwise give up after a reasonable time.
	 */
	while((mfpr(TXCS)&TXCS_RDY) == 0)
		if(--timo == 0)
			break;
	if(c == 0)
		return;
	s = mfpr(TXCS);
	mtpr(TXCS,0);
	mtpr(TXDB, c&0xff);
	if(c == '\n') {
		putchar('\r');
	}
	putchar(0);
	mtpr(TXCS, s);
}