Make pcvt and syscons live in the same kernel. If both are enabled, then

the first one in the config has priority.  They can be switched using
userconfig().

i386/i386/conf.c:
Initialize the shared syscons/pcvt cdevsw entry to `nx'.

Add cdevsw registration functions.

Use devsw functions of the correct type if they exist.

i386/i386/cons.c:
Add renamed syscons entry points to constab.

i386/i386/cons.h:
Declare the renamed syscons entry points.

i386/i386/machdep.c:
Repeat console initialization after userconfig() in case the current
console has become wrong.  This depends on cn functions not wiring down
anything important.

sys/conf.h:
Declare new functions.

i386/isa/isa.[ch]:
Add a function to decide which display driver has priority.  Should be
done better.

i386/isa/syscons.c:
Rename pccn* -> sccn*.

Initialize CRTC start address in case the previous driver has moved it.

i386/isa/syscons.c, i386/isa/pcvt/*
Initialize the bogusly shared variable Crtat dynamically in case the
stored value was changed by the previous driver.

Initialize cdevsw table from a template.

Don't grab the console if another display driver has priority.

i386/isa/syscons.h, i386/isa/pcvt/pcvt_hdr.h:
Don't externally declare now-static cdevsw functions.

i386/isa/pcvt/pcvt_hdr.h:
Set the sensitive hardware flag so that pcvt doesn't always have lower
priority than syscons.  This also fixes the "stupid" detection of the
display after filling the display with text.

i386/isa/pcvt/pcvt_out.c:
Don't be confused the off-screen cursor offset 0xffff set by syscons.

kern/subr_xxx.c:
Add enough nxio/nodev/null devsw functions of the correct type for syscons
and pcvt.

22 files changed, 483 insertions, 190 deletions

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index df465fa..cc934e1 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.140 1995/09/08 03:19:47 davidg Exp $
+ *	$Id: machdep.c,v 1.141 1995/09/09 18:09:45 davidg Exp $
  */
 
 #include "npx.h"
@@ -375,8 +375,10 @@ again:
 	for (i = 1; i < ncallout; i++)
 		callout[i-1].c_next = &callout[i];
 
-        if (boothowto & RB_CONFIG)
+        if (boothowto & RB_CONFIG) {
 		userconfig();
+		cninit();	/* the preferred console may have changed */
+	}
 
 #ifdef BOUNCE_BUFFERS
 	/*
@@ -1256,8 +1258,7 @@ init386(first)
 	/*
 	 * Initialize the console before we print anything out.
 	 */
-
-	cninit ();
+	cninit();
 
 	/*
 	 * make gdt memory segments, the code segment goes up to end of the
diff --git a/sys/amd64/isa/isa.c b/sys/amd64/isa/isa.c
index 1dd0fb9..51dd7f9 100644
--- a/sys/amd64/isa/isa.c
+++ b/sys/amd64/isa/isa.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)isa.c	7.2 (Berkeley) 5/13/91
- *	$Id: isa.c,v 1.49 1995/05/13 00:09:38 jkh Exp $
+ *	$Id: isa.c,v 1.50 1995/05/30 08:02:35 rgrimes Exp $
  */
 
 /*
@@ -910,6 +910,22 @@ isa_strayintr(d)
 }
 
 /*
+ * Find the highest priority enabled display device.  Since we can't
+ * distinguish display devices from ttys, depend on display devices
+ * being before serial ttys in the table.
+ */
+struct isa_device *
+find_display()
+{
+	struct isa_device *dvp;
+
+	for (dvp = isa_devtab_tty; dvp->id_driver != NULL; dvp++)
+		if (dvp->id_enabled)
+			return (dvp);
+	return (NULL);
+}
+
+/*
  * find an ISA device in a given isa_devtab_* table, given
  * the table to search, the expected id_driver entry, and the unit number.
  *
diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 8619dc9..8ab9c9c 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.123 1995/08/08 05:14:40 dyson Exp $
+ *  $Id: syscons.c,v 1.124 1995/08/16 22:36:43 nate Exp $
  */
 
 #include "sc.h"
@@ -47,6 +47,7 @@
 #include <sys/devconf.h>
 
 #include <machine/clock.h>
+#include <machine/cons.h>
 #include <machine/console.h>
 #include <machine/psl.h>
 #include <machine/frame.h>
@@ -57,7 +58,6 @@
 #include <i386/isa/isa_device.h>
 #include <i386/isa/timerreg.h>
 #include <i386/isa/kbdtables.h>
-#include <i386/i386/cons.h>
 #include <i386/isa/syscons.h>
 
 #if !defined(MAXCONS)
@@ -132,7 +132,7 @@ int			nsccons = MAXCONS+1;
 #endif
 #define MONO_BUF    	pa_to_va(0xB0000)
 #define CGA_BUF     	pa_to_va(0xB8000)
-u_short         	*Crtat = (u_short *)MONO_BUF;
+u_short         	*Crtat;
 
 #define WRAPHIST(scp, pointer, offset)\
     ((scp->history) + ((((pointer) - (scp->history)) + (scp->history_size)\
@@ -142,6 +142,20 @@ struct  isa_driver scdriver = {
     scprobe, scattach, "sc", 1
 };
 
+static	d_open_t	scopen;
+static	d_close_t	scclose;
+static	d_rdwr_t	scread;
+static	d_rdwr_t	scwrite;
+static	d_ioctl_t	scioctl;
+static	d_ttycv_t	scdevtotty;
+static	d_mmap_t	scmmap;
+
+static	struct cdevsw	scdevsw = {
+	scopen,		scclose,	scread,		scwrite,
+	scioctl,	nullstop,	noreset,	scdevtotty,
+	ttselect,	scmmap,		nostrategy,
+};
+
 int
 scprobe(struct isa_device *dev)
 {
@@ -295,6 +309,9 @@ scattach(struct isa_device *dev)
     scp->r_hook.ah_order = APM_MID_ORDER;
     apm_hook_establish(APM_HOOK_RESUME , &scp->r_hook);
 #endif
+
+    register_cdev("sc", &scdevsw);
+
     return 0;
 }
 
@@ -1107,14 +1124,20 @@ scstart(struct tty *tp)
 }
 
 void
-pccnprobe(struct consdev *cp)
+sccnprobe(struct consdev *cp)
 {
+    struct isa_device *dvp;
     int maj;
 
-    /* locate the major number */
-    for (maj = 0; maj < nchrdev; maj++)
-	if ((void*)cdevsw[maj].d_open == (void*)scopen)
-	    break;
+    /*
+     * Take control if we are the highest priority enabled display device.
+     */
+    dvp = find_display();
+    maj = getmajorbyname("sc");
+    if (dvp->id_driver != &scdriver || maj < 0) {
+	cp->cn_pri = CN_DEAD;
+	return;
+    }
 
     /* initialize required fields */
     cp->cn_dev = makedev(maj, MAXCONS);
@@ -1122,13 +1145,13 @@ pccnprobe(struct consdev *cp)
 }
 
 void
-pccninit(struct consdev *cp)
+sccninit(struct consdev *cp)
 {
     scinit();
 }
 
 void
-pccnputc(dev_t dev, int c)
+sccnputc(dev_t dev, int c)
 {
     u_char buf[1];
     scr_stat *scp = console[0];
@@ -1156,7 +1179,7 @@ pccnputc(dev_t dev, int c)
 }
 
 int
-pccngetc(dev_t dev)
+sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
     int c = scgetc(0);
@@ -1165,7 +1188,7 @@ pccngetc(dev_t dev)
 }
 
 int
-pccncheckc(dev_t dev)
+sccncheckc(dev_t dev)
 {
     return (scgetc(1) & 0xff);
 }
@@ -1945,27 +1968,42 @@ outloop:
 static void
 scinit(void)
 {
-    u_short volatile *cp = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short), was;
-    unsigned hw_cursor;
+    u_short volatile *cp;
+    u_short was;
+    unsigned hw_cursor, startaddr;
     int i;
 
     if (init_done)
 	return;
     init_done = TRUE;
     /*
-     * Crtat initialized to point to MONO buffer, if not present change
-     * to CGA_BUF offset. ONLY add the difference since locore.s adds
-     * in the remapped offset at the "right" time
+     * Finish defaulting crtc variables for a mono screen.  Crtat is a
+     * bogus common variable so that it can be shared with pcvt, so it
+     * can't be statically initialized.  XXX.
+     */
+     Crtat = (u_short *)MONO_BUF;
+    /*
+     * If CGA memory seems to work, switch to color.
      */
+    cp = (u_short *)CGA_BUF;
     was = *cp;
     *cp = (u_short) 0xA55A;
-    if (*cp != 0xA55A)
-	crtc_addr = MONO_BASE;
-    else {
-	*cp = was;
+    if (*cp == 0xA55A) {
+	Crtat = (u_short *)cp;
 	crtc_addr = COLOR_BASE;
-	Crtat = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short);
     }
+    *cp = was;
+
+    /*
+     * Ensure a zero start address.  This is mainly to recover after
+     * switching from pcvt using userconfig().  The registers are r/o
+     * for old hardware so it's too hard to relocate the active screen
+     * memory.
+     */
+    outb(crtc_addr, 12);
+    outb(crtc_addr + 1, 0);
+    outb(crtc_addr, 13);
+    outb(crtc_addr + 1, 0);
 
     /* extract cursor location */
     outb(crtc_addr, 14);
diff --git a/sys/dev/syscons/syscons.h b/sys/dev/syscons/syscons.h
index b09c57e..e660ba7 100644
--- a/sys/dev/syscons/syscons.h
+++ b/sys/dev/syscons/syscons.h
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: syscons.h,v 1.9 1995/05/30 08:03:15 rgrimes Exp $
+ *	$Id: syscons.h,v 1.10 1995/07/11 18:34:30 bde Exp $
  */
 
 #ifndef _I386_ISA_SYSCONS_H_
@@ -168,18 +168,11 @@ typedef struct default_attr {
 /* function prototypes */
 int scprobe(struct isa_device *dev);
 int scattach(struct isa_device *dev);
-int scopen(dev_t dev, int flag, int mode, struct proc *p);
-int scclose(dev_t dev, int flag, int mode, struct proc *p);
-int scread(dev_t dev, struct uio *uio, int flag);
-int scwrite(dev_t dev, struct uio *uio, int flag);
 int scparam(struct tty *tp, struct termios *t);
-int scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p);
 void scstart(struct tty *tp);
 void scintr(int unit);
-int pcmmap(dev_t dev, int offset, int nprot);
 static void scinit(void);
 static u_int scgetc(int noblock);
-       struct tty *scdevtotty(dev_t dev);
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
diff --git a/sys/i386/i386/conf.c b/sys/i386/i386/conf.c
index 4fc699a..474484d 100644
--- a/sys/i386/i386/conf.c
+++ b/sys/i386/i386/conf.c
@@ -42,7 +42,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)conf.c	5.8 (Berkeley) 5/12/91
- *	$Id: conf.c,v 1.96 1995/09/08 03:37:51 julian Exp $
+ *	$Id: conf.c,v 1.97 1995/09/09 18:09:43 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -63,10 +63,8 @@ d_rdwr_t rawread, rawwrite;
 #define nowrite		noread
 #define noioc		(d_ioctl_t *)enodev
 #define nostop		(d_stop_t *)enodev
-#define noreset		(d_reset_t *)enodev
 #define noselect	(d_select_t *)enodev
-#define nommap		(d_mmap_t *)enodev
-#define nostrat		(d_strategy_t *)enodev
+#define nostrat		nostrategy
 #define nodump		(d_dump_t *)enodev
 #define	nodevtotty	(d_ttycv_t *)nullop
 
@@ -83,11 +81,6 @@ d_rdwr_t rawread, rawwrite;
 #define nxmmap		(d_mmap_t *)enxio
 #define	nxdevtotty	(d_ttycv_t *)nullop
 
-#define nullopen	(d_open_t *)nullop
-#define nullclose	(d_close_t *)nullop
-#define nullstop	(d_stop_t *)nullop
-#define nullreset	(d_reset_t *)nullop
-
 #define zerosize	(d_psize_t *)0
 
 int lkmenodev();
@@ -470,43 +463,6 @@ int	nblkdev = sizeof (bdevsw) / sizeof (bdevsw[0]);
 /* console */
 #include "machine/cons.h"
 
-/* more console */
-#include "sc.h"
-#include "vt.h"
-#if NSC > 0
-# if NVT > 0 && !defined(LINT)
-#  error "sc0 and vt0 are mutually exclusive"
-# endif
-d_open_t	scopen;
-d_close_t	scclose;
-d_rdwr_t	scread, scwrite;
-d_ioctl_t	scioctl;
-d_mmap_t	scmmap;
-d_ttycv_t	scdevtotty;
-#elif NVT > 0
-d_open_t	pcopen;
-d_close_t	pcclose;
-d_rdwr_t	pcread, pcwrite;
-d_ioctl_t	pcioctl;
-d_mmap_t	pcmmap;
-d_ttycv_t	pcdevtotty;
-#define scopen		pcopen
-#define scclose		pcclose
-#define scread		pcread
-#define scwrite		pcwrite
-#define scioctl		pcioctl
-#define scmmap		pcmmap
-#define	scdevtotty	pcdevtotty
-#else  /* neither syscons nor pcvt, i.e. no grafx console driver */
-#define scopen		nxopen
-#define scclose		nxclose
-#define scread		nxread
-#define scwrite		nxwrite
-#define scioctl		nxioctl
-#define scmmap		nxmmap
-#define	scdevtotty	nxdevtotty
-#endif /* NSC > 0, NVT > 0 */
-
 /* /dev/mem */
 d_open_t	mmopen;
 d_close_t	mmclose;
@@ -1166,9 +1122,9 @@ struct cdevsw	cdevsw[] =
 	{ spigot_open,	spigot_close,	spigot_read,	spigot_write,	/*11*/
 	  spigot_ioctl,	nostop,		nullreset,	nodevtotty,/* Spigot */
 	  spigot_select, spigot_mmap,	NULL },
-	{ scopen,	scclose,	scread,		scwrite,	/*12*/
-	  scioctl,	nullstop,	nullreset,	scdevtotty,/* sc */
-	  ttselect,	scmmap,		NULL },
+	{ nxopen,	nxclose,	nxread,		nxwrite,	/*12*/
+	  nxioctl,	nxstop,		nxreset,	nxdevtotty,/* sc, ... */
+	  nxselect,	nxmmap,		NULL },
 	{ sdopen,	sdclose,	rawread,	rawwrite,	/*13*/
 	  sdioctl,	nostop,		nullreset,	nodevtotty,/* sd */
 	  seltrue,	nommap,		sdstrategy },
@@ -1469,3 +1425,65 @@ chrtoblk(dev)
 	}
 	return (makedev(blkmaj, minor(dev)));
 }
+
+int
+getmajorbyname(name)
+	const char *name;
+{
+
+	if (strcmp(name, "sc") == 0)
+		return (12);
+	if (strcmp(name, "vt") == 0)
+		return (12);
+	return (NULL);
+}
+
+
+static struct cdevsw *getcdevbyname __P((const char *name));
+static struct cdevsw *
+getcdevbyname(name)
+	const char *name;
+{
+	int maj;
+
+	maj = getmajorbyname(name);
+	return (maj < 0 ? NULL : &cdevsw[maj]);
+}
+
+int
+register_cdev(name, cdp)
+	const char *name;
+	const struct cdevsw *cdp;
+{
+	struct cdevsw *dst_cdp;
+
+	dst_cdp = getcdevbyname(name);
+	if (dst_cdp == NULL)
+		return (ENXIO);
+	if (dst_cdp->d_open != nxopen)
+		return (EBUSY);
+	*dst_cdp = *cdp;
+	return (0);
+}
+
+static struct cdevsw nxcdevsw = {
+	nxopen,		nxclose,	nxread,		nxwrite,
+	nxioctl,	nxstop,		nxreset,	nxdevtotty,
+	nxselect,	nxmmap,		NULL,
+};
+
+int
+unregister_cdev(name, cdp)
+	const char *name;
+	const struct cdevsw *cdp;
+{
+	struct cdevsw *dst_cdp;
+
+	dst_cdp = getcdevbyname(name);
+	if (dst_cdp == NULL)
+		return (ENXIO);
+	if (dst_cdp->d_open != cdp->d_open)
+		return (EBUSY);
+	*dst_cdp = nxcdevsw;
+	return (0);
+}
diff --git a/sys/i386/i386/cons.c b/sys/i386/i386/cons.c
index 7cddb5e..0b509594 100644
--- a/sys/i386/i386/cons.c
+++ b/sys/i386/i386/cons.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
- *	$Id: cons.c,v 1.32 1995/09/09 18:09:44 davidg Exp $
+ *	$Id: cons.c,v 1.33 1995/09/10 18:57:25 bde Exp $
  */
 
 #include <sys/param.h>
@@ -53,7 +53,10 @@
 #include "vt.h"
 #include "sio.h"
 static struct consdev constab[] = {
-#if NSC > 0 || NVT > 0
+#if NSC > 0
+	{ sccnprobe,	sccninit,	sccngetc,	sccncheckc,	sccnputc },
+#endif
+#if NVT > 0
 	{ pccnprobe,	pccninit,	pccngetc,	pccncheckc,	pccnputc },
 #endif
 #if NSIO > 0
diff --git a/sys/i386/i386/cons.h b/sys/i386/i386/cons.h
index 35d919a..8fbd43f 100644
--- a/sys/i386/i386/cons.h
+++ b/sys/i386/i386/cons.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)cons.h	7.2 (Berkeley) 5/9/91
- *	$Id: cons.h,v 1.9 1995/04/24 16:43:01 bde Exp $
+ *	$Id: cons.h,v 1.10 1995/09/10 18:57:26 bde Exp $
  */
 
 #ifndef _MACHINE_CONS_H_
@@ -60,6 +60,12 @@ cn_getc_t	pccngetc;
 cn_checkc_t	pccncheckc;
 cn_putc_t	pccnputc;
 
+cn_probe_t	sccnprobe;
+cn_init_t	sccninit;
+cn_getc_t	sccngetc;
+cn_checkc_t	sccncheckc;
+cn_putc_t	sccnputc;
+
 cn_probe_t	siocnprobe;
 cn_init_t	siocninit;
 cn_getc_t	siocngetc;
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index df465fa..cc934e1 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.140 1995/09/08 03:19:47 davidg Exp $
+ *	$Id: machdep.c,v 1.141 1995/09/09 18:09:45 davidg Exp $
  */
 
 #include "npx.h"
@@ -375,8 +375,10 @@ again:
 	for (i = 1; i < ncallout; i++)
 		callout[i-1].c_next = &callout[i];
 
-        if (boothowto & RB_CONFIG)
+        if (boothowto & RB_CONFIG) {
 		userconfig();
+		cninit();	/* the preferred console may have changed */
+	}
 
 #ifdef BOUNCE_BUFFERS
 	/*
@@ -1256,8 +1258,7 @@ init386(first)
 	/*
 	 * Initialize the console before we print anything out.
 	 */
-
-	cninit ();
+	cninit();
 
 	/*
 	 * make gdt memory segments, the code segment goes up to end of the
diff --git a/sys/i386/isa/isa.c b/sys/i386/isa/isa.c
index 1dd0fb9..51dd7f9 100644
--- a/sys/i386/isa/isa.c
+++ b/sys/i386/isa/isa.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)isa.c	7.2 (Berkeley) 5/13/91
- *	$Id: isa.c,v 1.49 1995/05/13 00:09:38 jkh Exp $
+ *	$Id: isa.c,v 1.50 1995/05/30 08:02:35 rgrimes Exp $
  */
 
 /*
@@ -910,6 +910,22 @@ isa_strayintr(d)
 }
 
 /*
+ * Find the highest priority enabled display device.  Since we can't
+ * distinguish display devices from ttys, depend on display devices
+ * being before serial ttys in the table.
+ */
+struct isa_device *
+find_display()
+{
+	struct isa_device *dvp;
+
+	for (dvp = isa_devtab_tty; dvp->id_driver != NULL; dvp++)
+		if (dvp->id_enabled)
+			return (dvp);
+	return (NULL);
+}
+
+/*
  * find an ISA device in a given isa_devtab_* table, given
  * the table to search, the expected id_driver entry, and the unit number.
  *
diff --git a/sys/i386/isa/isa_device.h b/sys/i386/isa/isa_device.h
index 4e3c08c..d201dae 100644
--- a/sys/i386/isa/isa_device.h
+++ b/sys/i386/isa/isa_device.h
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)isa_device.h	7.1 (Berkeley) 5/9/91
- *	$Id: isa_device.h,v 1.22 1995/05/11 02:15:55 jkh Exp $
+ *	$Id: isa_device.h,v 1.23 1995/05/11 07:41:52 jkh Exp $
  */
 
 #ifndef _I386_ISA_ISA_DEVICE_H_
@@ -134,14 +134,15 @@ inthand_t
 	IDTVEC(fastintr10), IDTVEC(fastintr11),
 	IDTVEC(fastintr12), IDTVEC(fastintr13),
 	IDTVEC(fastintr14), IDTVEC(fastintr15);
-struct isa_device *find_isadev __P((struct isa_device *table,
-				    struct isa_driver *driverp, int unit));
 inthand_t
 	IDTVEC(intr0), IDTVEC(intr1), IDTVEC(intr2), IDTVEC(intr3),
 	IDTVEC(intr4), IDTVEC(intr5), IDTVEC(intr6), IDTVEC(intr7),
 	IDTVEC(intr8), IDTVEC(intr9), IDTVEC(intr10), IDTVEC(intr11),
 	IDTVEC(intr12), IDTVEC(intr13), IDTVEC(intr14), IDTVEC(intr15);
 
+struct isa_device *find_display __P((void));
+struct isa_device *find_isadev __P((struct isa_device *table,
+				    struct isa_driver *driverp, int unit));
 void isa_configure __P((void));
 int haveseen_isadev __P((struct isa_device *dvp, u_int checkbits));
 void isa_defaultirq __P((void));
diff --git a/sys/i386/isa/pcvt/pcvt_drv.c b/sys/i386/isa/pcvt/pcvt_drv.c
index cdf3073..dc91d47 100644
--- a/sys/i386/isa/pcvt/pcvt_drv.c
+++ b/sys/i386/isa/pcvt/pcvt_drv.c
@@ -105,6 +105,20 @@ static char vt_description[];
 #define VT_DESCR_LEN 40
 #endif /* PCVT_FREEBSD > 205 */
 
+static	d_open_t	pcopen;
+static	d_close_t	pcclose;
+static	d_rdwr_t	pcread;
+static	d_rdwr_t	pcwrite;
+static	d_ioctl_t	pcioctl;
+static	d_ttycv_t	pcdevtotty;
+static	d_mmap_t	pcmmap;
+
+static	struct cdevsw	pcdevsw = {
+	pcopen,		pcclose,	pcread,		pcwrite,
+	pcioctl,	nullstop,	noreset,	pcdevtotty,
+	ttselect,	pcmmap,		nostrategy,
+};
+
 #if PCVT_NETBSD > 100	/* NetBSD-current Feb 20 1995 */
 int
 pcprobe(struct device *parent, void *match, void *aux)
@@ -309,6 +323,8 @@ pcattach(struct isa_device *dev)
 	kdc_vt[dev->id_unit].kdc_state =
 		pcvt_is_console? DC_IDLE: DC_BUSY;
 	vt_registerdev(dev, (char *)vga_string(vga_type));
+
+	register_cdev("vt", &pcdevsw);
 #endif /* PCVT_FREEBSD > 205 */
 
 #if PCVT_NETBSD > 9
@@ -1086,20 +1102,17 @@ int
 #endif
 pccnprobe(struct consdev *cp)
 {
+	struct isa_device *dvp;
 	int maj;
 
-	/* locate the major number */
-
-	for (maj = 0; maj < nchrdev; maj++)
-	{
-		if ((u_int)cdevsw[maj].d_open == (u_int)pcopen)
-			break;
-	}
-
-	if (maj == nchrdev)
-	{
-		/* we are not in cdevsw[], give up */
-		panic("pcvt is not in cdevsw[]");
+	/*
+	 * Take control if we are the highest priority enabled display device.
+	 */
+	dvp = find_display();
+	maj = getmajorbyname("vt");
+	if (dvp->id_driver != &vtdriver || maj < 0) {
+		cp->cn_pri = CN_DEAD;
+		return;
 	}
 
 	/* initialize required fields */
diff --git a/sys/i386/isa/pcvt/pcvt_hdr.h b/sys/i386/isa/pcvt/pcvt_hdr.h
index 7f0ad9e..d84942a 100644
--- a/sys/i386/isa/pcvt/pcvt_hdr.h
+++ b/sys/i386/isa/pcvt/pcvt_hdr.h
@@ -132,7 +132,7 @@
 #if PCVT_NETBSD > 9
 #include "dev/cons.h"
 #elif PCVT_FREEBSD >= 200
-#include <i386/i386/cons.h>
+#include <machine/cons.h>
 #else
 #include "i386/i386/cons.h"
 #endif
@@ -943,7 +943,7 @@ int pcprobe ( struct isa_device *dev );
 int pcattach ( struct isa_device *dev );
 
 struct	isa_driver vtdriver = {		/* driver routines */
-	pcprobe, pcattach, "vt",
+	pcprobe, pcattach, "vt", 1,
 };
 
 #endif /* PCVT_NETBSD > 9 */
@@ -959,7 +959,8 @@ u_char bgansitopc[] = {			/* background ANSI color -> pc */
 };
 
 #if !PCVT_NETBSD
-u_short *Crtat	=	(u_short *)MONO_BUF;	/* screen start address */
+/* XXX Crtat is shared with syscons. */
+u_short *Crtat;			/* screen start address */
 #if !(PCVT_FREEBSD > 110 && PCVT_FREEBSD < 200)
 struct tty *pcconsp =	&pccons[0];		/* ptr to current device */
 #else /* PCVT_FREEBSD > 110 */
@@ -1210,20 +1211,11 @@ extern void bcopyb(void *from, void *to, u_int length);
 extern void fillw(U_short value, void *addr, u_int length);
 #endif
 
-int	pcopen ( Dev_t dev, int flag, int mode, struct proc *p );
-int	pcclose ( Dev_t dev, int flag, int mode, struct proc *p );
-int	pcread ( Dev_t dev, struct uio *uio, int flag );
-int	pcwrite ( Dev_t dev, struct uio *uio, int flag );
-int	pcioctl ( Dev_t dev, int cmd, caddr_t data, int flag, struct proc *p );
-int	pcmmap ( Dev_t dev, int offset, int nprot );
-#if PCVT_FREEBSD > 205
-struct tty *pcdevtotty ( Dev_t dev );
-#endif /* PCVT_FREEBSD > 205 */
 int	pcrint ( void );
 int	pcparam ( struct tty *tp, struct termios *t );
 
 /*
- * In FreeBSD > 2.0.6, driver console functions are declared in i386/cons.h
+ * In FreeBSD > 2.0.6, driver console functions are declared in machine/cons.h
  * and some return void, so don't declare them here.
  */
 #if PCVT_FREEBSD <= 205
diff --git a/sys/i386/isa/pcvt/pcvt_out.c b/sys/i386/isa/pcvt/pcvt_out.c
index 945ee24..fc76517 100644
--- a/sys/i386/isa/pcvt/pcvt_out.c
+++ b/sys/i386/isa/pcvt/pcvt_out.c
@@ -892,13 +892,17 @@ sput (u_char *s, U_char kernel, int len, int page)
 static void
 vt_coldinit(void)
 {
-	u_short volatile *cp = Crtat + (CGA_BUF-MONO_BUF)/CHR;
+	u_short volatile *cp;
 	u_short was;
 	int nscr, charset;
 	int equipment;
-	u_short *SaveCrtat = Crtat;
+	u_short *SaveCrtat;
 	struct video_state *svsp;
 
+	Crtat = (u_short *)MONO_BUF;	/* XXX assume static relocation works */
+	SaveCrtat = Crtat;
+	cp = Crtat + (CGA_BUF-MONO_BUF)/CHR;
+
 	do_initialization = 0;		/* reset init necessary flag */
 
 	/* get the equipment byte from the RTC chip */
@@ -1121,6 +1125,16 @@ vt_coldinit(void)
 			outb(addr_6845, CRTC_CURSORL);
 			cursorat |= inb(addr_6845+1);
 
+			/*
+			 * Reject cursors that are more than one row off a
+			 * 25-row screen.  syscons sets the cursor offset
+			 * to 0xffff. The scroll up fixup fails for this
+			 * because the assignment to svsp->row overflows
+			 * and perhaps for other reasons.
+			 */
+			if (cursorat > 25 * svsp->maxcol)
+				cursorat = 25 * svsp->maxcol;
+
 			svsp->cur_offset = cursorat;
 			svsp->row = cursorat / svsp->maxcol;
 			svsp->col = cursorat % svsp->maxcol;
diff --git a/sys/i386/isa/syscons.c b/sys/i386/isa/syscons.c
index 8619dc9..8ab9c9c 100644
--- a/sys/i386/isa/syscons.c
+++ b/sys/i386/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.123 1995/08/08 05:14:40 dyson Exp $
+ *  $Id: syscons.c,v 1.124 1995/08/16 22:36:43 nate Exp $
  */
 
 #include "sc.h"
@@ -47,6 +47,7 @@
 #include <sys/devconf.h>
 
 #include <machine/clock.h>
+#include <machine/cons.h>
 #include <machine/console.h>
 #include <machine/psl.h>
 #include <machine/frame.h>
@@ -57,7 +58,6 @@
 #include <i386/isa/isa_device.h>
 #include <i386/isa/timerreg.h>
 #include <i386/isa/kbdtables.h>
-#include <i386/i386/cons.h>
 #include <i386/isa/syscons.h>
 
 #if !defined(MAXCONS)
@@ -132,7 +132,7 @@ int			nsccons = MAXCONS+1;
 #endif
 #define MONO_BUF    	pa_to_va(0xB0000)
 #define CGA_BUF     	pa_to_va(0xB8000)
-u_short         	*Crtat = (u_short *)MONO_BUF;
+u_short         	*Crtat;
 
 #define WRAPHIST(scp, pointer, offset)\
     ((scp->history) + ((((pointer) - (scp->history)) + (scp->history_size)\
@@ -142,6 +142,20 @@ struct  isa_driver scdriver = {
     scprobe, scattach, "sc", 1
 };
 
+static	d_open_t	scopen;
+static	d_close_t	scclose;
+static	d_rdwr_t	scread;
+static	d_rdwr_t	scwrite;
+static	d_ioctl_t	scioctl;
+static	d_ttycv_t	scdevtotty;
+static	d_mmap_t	scmmap;
+
+static	struct cdevsw	scdevsw = {
+	scopen,		scclose,	scread,		scwrite,
+	scioctl,	nullstop,	noreset,	scdevtotty,
+	ttselect,	scmmap,		nostrategy,
+};
+
 int
 scprobe(struct isa_device *dev)
 {
@@ -295,6 +309,9 @@ scattach(struct isa_device *dev)
     scp->r_hook.ah_order = APM_MID_ORDER;
     apm_hook_establish(APM_HOOK_RESUME , &scp->r_hook);
 #endif
+
+    register_cdev("sc", &scdevsw);
+
     return 0;
 }
 
@@ -1107,14 +1124,20 @@ scstart(struct tty *tp)
 }
 
 void
-pccnprobe(struct consdev *cp)
+sccnprobe(struct consdev *cp)
 {
+    struct isa_device *dvp;
     int maj;
 
-    /* locate the major number */
-    for (maj = 0; maj < nchrdev; maj++)
-	if ((void*)cdevsw[maj].d_open == (void*)scopen)
-	    break;
+    /*
+     * Take control if we are the highest priority enabled display device.
+     */
+    dvp = find_display();
+    maj = getmajorbyname("sc");
+    if (dvp->id_driver != &scdriver || maj < 0) {
+	cp->cn_pri = CN_DEAD;
+	return;
+    }
 
     /* initialize required fields */
     cp->cn_dev = makedev(maj, MAXCONS);
@@ -1122,13 +1145,13 @@ pccnprobe(struct consdev *cp)
 }
 
 void
-pccninit(struct consdev *cp)
+sccninit(struct consdev *cp)
 {
     scinit();
 }
 
 void
-pccnputc(dev_t dev, int c)
+sccnputc(dev_t dev, int c)
 {
     u_char buf[1];
     scr_stat *scp = console[0];
@@ -1156,7 +1179,7 @@ pccnputc(dev_t dev, int c)
 }
 
 int
-pccngetc(dev_t dev)
+sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
     int c = scgetc(0);
@@ -1165,7 +1188,7 @@ pccngetc(dev_t dev)
 }
 
 int
-pccncheckc(dev_t dev)
+sccncheckc(dev_t dev)
 {
     return (scgetc(1) & 0xff);
 }
@@ -1945,27 +1968,42 @@ outloop:
 static void
 scinit(void)
 {
-    u_short volatile *cp = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short), was;
-    unsigned hw_cursor;
+    u_short volatile *cp;
+    u_short was;
+    unsigned hw_cursor, startaddr;
     int i;
 
     if (init_done)
 	return;
     init_done = TRUE;
     /*
-     * Crtat initialized to point to MONO buffer, if not present change
-     * to CGA_BUF offset. ONLY add the difference since locore.s adds
-     * in the remapped offset at the "right" time
+     * Finish defaulting crtc variables for a mono screen.  Crtat is a
+     * bogus common variable so that it can be shared with pcvt, so it
+     * can't be statically initialized.  XXX.
+     */
+     Crtat = (u_short *)MONO_BUF;
+    /*
+     * If CGA memory seems to work, switch to color.
      */
+    cp = (u_short *)CGA_BUF;
     was = *cp;
     *cp = (u_short) 0xA55A;
-    if (*cp != 0xA55A)
-	crtc_addr = MONO_BASE;
-    else {
-	*cp = was;
+    if (*cp == 0xA55A) {
+	Crtat = (u_short *)cp;
 	crtc_addr = COLOR_BASE;
-	Crtat = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short);
     }
+    *cp = was;
+
+    /*
+     * Ensure a zero start address.  This is mainly to recover after
+     * switching from pcvt using userconfig().  The registers are r/o
+     * for old hardware so it's too hard to relocate the active screen
+     * memory.
+     */
+    outb(crtc_addr, 12);
+    outb(crtc_addr + 1, 0);
+    outb(crtc_addr, 13);
+    outb(crtc_addr + 1, 0);
 
     /* extract cursor location */
     outb(crtc_addr, 14);
diff --git a/sys/i386/isa/syscons.h b/sys/i386/isa/syscons.h
index b09c57e..e660ba7 100644
--- a/sys/i386/isa/syscons.h
+++ b/sys/i386/isa/syscons.h
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: syscons.h,v 1.9 1995/05/30 08:03:15 rgrimes Exp $
+ *	$Id: syscons.h,v 1.10 1995/07/11 18:34:30 bde Exp $
  */
 
 #ifndef _I386_ISA_SYSCONS_H_
@@ -168,18 +168,11 @@ typedef struct default_attr {
 /* function prototypes */
 int scprobe(struct isa_device *dev);
 int scattach(struct isa_device *dev);
-int scopen(dev_t dev, int flag, int mode, struct proc *p);
-int scclose(dev_t dev, int flag, int mode, struct proc *p);
-int scread(dev_t dev, struct uio *uio, int flag);
-int scwrite(dev_t dev, struct uio *uio, int flag);
 int scparam(struct tty *tp, struct termios *t);
-int scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p);
 void scstart(struct tty *tp);
 void scintr(int unit);
-int pcmmap(dev_t dev, int offset, int nprot);
 static void scinit(void);
 static u_int scgetc(int noblock);
-       struct tty *scdevtotty(dev_t dev);
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
diff --git a/sys/isa/syscons.c b/sys/isa/syscons.c
index 8619dc9..8ab9c9c 100644
--- a/sys/isa/syscons.c
+++ b/sys/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.123 1995/08/08 05:14:40 dyson Exp $
+ *  $Id: syscons.c,v 1.124 1995/08/16 22:36:43 nate Exp $
  */
 
 #include "sc.h"
@@ -47,6 +47,7 @@
 #include <sys/devconf.h>
 
 #include <machine/clock.h>
+#include <machine/cons.h>
 #include <machine/console.h>
 #include <machine/psl.h>
 #include <machine/frame.h>
@@ -57,7 +58,6 @@
 #include <i386/isa/isa_device.h>
 #include <i386/isa/timerreg.h>
 #include <i386/isa/kbdtables.h>
-#include <i386/i386/cons.h>
 #include <i386/isa/syscons.h>
 
 #if !defined(MAXCONS)
@@ -132,7 +132,7 @@ int			nsccons = MAXCONS+1;
 #endif
 #define MONO_BUF    	pa_to_va(0xB0000)
 #define CGA_BUF     	pa_to_va(0xB8000)
-u_short         	*Crtat = (u_short *)MONO_BUF;
+u_short         	*Crtat;
 
 #define WRAPHIST(scp, pointer, offset)\
     ((scp->history) + ((((pointer) - (scp->history)) + (scp->history_size)\
@@ -142,6 +142,20 @@ struct  isa_driver scdriver = {
     scprobe, scattach, "sc", 1
 };
 
+static	d_open_t	scopen;
+static	d_close_t	scclose;
+static	d_rdwr_t	scread;
+static	d_rdwr_t	scwrite;
+static	d_ioctl_t	scioctl;
+static	d_ttycv_t	scdevtotty;
+static	d_mmap_t	scmmap;
+
+static	struct cdevsw	scdevsw = {
+	scopen,		scclose,	scread,		scwrite,
+	scioctl,	nullstop,	noreset,	scdevtotty,
+	ttselect,	scmmap,		nostrategy,
+};
+
 int
 scprobe(struct isa_device *dev)
 {
@@ -295,6 +309,9 @@ scattach(struct isa_device *dev)
     scp->r_hook.ah_order = APM_MID_ORDER;
     apm_hook_establish(APM_HOOK_RESUME , &scp->r_hook);
 #endif
+
+    register_cdev("sc", &scdevsw);
+
     return 0;
 }
 
@@ -1107,14 +1124,20 @@ scstart(struct tty *tp)
 }
 
 void
-pccnprobe(struct consdev *cp)
+sccnprobe(struct consdev *cp)
 {
+    struct isa_device *dvp;
     int maj;
 
-    /* locate the major number */
-    for (maj = 0; maj < nchrdev; maj++)
-	if ((void*)cdevsw[maj].d_open == (void*)scopen)
-	    break;
+    /*
+     * Take control if we are the highest priority enabled display device.
+     */
+    dvp = find_display();
+    maj = getmajorbyname("sc");
+    if (dvp->id_driver != &scdriver || maj < 0) {
+	cp->cn_pri = CN_DEAD;
+	return;
+    }
 
     /* initialize required fields */
     cp->cn_dev = makedev(maj, MAXCONS);
@@ -1122,13 +1145,13 @@ pccnprobe(struct consdev *cp)
 }
 
 void
-pccninit(struct consdev *cp)
+sccninit(struct consdev *cp)
 {
     scinit();
 }
 
 void
-pccnputc(dev_t dev, int c)
+sccnputc(dev_t dev, int c)
 {
     u_char buf[1];
     scr_stat *scp = console[0];
@@ -1156,7 +1179,7 @@ pccnputc(dev_t dev, int c)
 }
 
 int
-pccngetc(dev_t dev)
+sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
     int c = scgetc(0);
@@ -1165,7 +1188,7 @@ pccngetc(dev_t dev)
 }
 
 int
-pccncheckc(dev_t dev)
+sccncheckc(dev_t dev)
 {
     return (scgetc(1) & 0xff);
 }
@@ -1945,27 +1968,42 @@ outloop:
 static void
 scinit(void)
 {
-    u_short volatile *cp = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short), was;
-    unsigned hw_cursor;
+    u_short volatile *cp;
+    u_short was;
+    unsigned hw_cursor, startaddr;
     int i;
 
     if (init_done)
 	return;
     init_done = TRUE;
     /*
-     * Crtat initialized to point to MONO buffer, if not present change
-     * to CGA_BUF offset. ONLY add the difference since locore.s adds
-     * in the remapped offset at the "right" time
+     * Finish defaulting crtc variables for a mono screen.  Crtat is a
+     * bogus common variable so that it can be shared with pcvt, so it
+     * can't be statically initialized.  XXX.
+     */
+     Crtat = (u_short *)MONO_BUF;
+    /*
+     * If CGA memory seems to work, switch to color.
      */
+    cp = (u_short *)CGA_BUF;
     was = *cp;
     *cp = (u_short) 0xA55A;
-    if (*cp != 0xA55A)
-	crtc_addr = MONO_BASE;
-    else {
-	*cp = was;
+    if (*cp == 0xA55A) {
+	Crtat = (u_short *)cp;
 	crtc_addr = COLOR_BASE;
-	Crtat = Crtat + (CGA_BUF-MONO_BUF)/sizeof(u_short);
     }
+    *cp = was;
+
+    /*
+     * Ensure a zero start address.  This is mainly to recover after
+     * switching from pcvt using userconfig().  The registers are r/o
+     * for old hardware so it's too hard to relocate the active screen
+     * memory.
+     */
+    outb(crtc_addr, 12);
+    outb(crtc_addr + 1, 0);
+    outb(crtc_addr, 13);
+    outb(crtc_addr + 1, 0);
 
     /* extract cursor location */
     outb(crtc_addr, 14);
diff --git a/sys/isa/syscons.h b/sys/isa/syscons.h
index b09c57e..e660ba7 100644
--- a/sys/isa/syscons.h
+++ b/sys/isa/syscons.h
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: syscons.h,v 1.9 1995/05/30 08:03:15 rgrimes Exp $
+ *	$Id: syscons.h,v 1.10 1995/07/11 18:34:30 bde Exp $
  */
 
 #ifndef _I386_ISA_SYSCONS_H_
@@ -168,18 +168,11 @@ typedef struct default_attr {
 /* function prototypes */
 int scprobe(struct isa_device *dev);
 int scattach(struct isa_device *dev);
-int scopen(dev_t dev, int flag, int mode, struct proc *p);
-int scclose(dev_t dev, int flag, int mode, struct proc *p);
-int scread(dev_t dev, struct uio *uio, int flag);
-int scwrite(dev_t dev, struct uio *uio, int flag);
 int scparam(struct tty *tp, struct termios *t);
-int scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p);
 void scstart(struct tty *tp);
 void scintr(int unit);
-int pcmmap(dev_t dev, int offset, int nprot);
 static void scinit(void);
 static u_int scgetc(int noblock);
-       struct tty *scdevtotty(dev_t dev);
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
diff --git a/sys/kern/subr_xxx.c b/sys/kern/subr_xxx.c
index e866b8a..b0a0817 100644
--- a/sys/kern/subr_xxx.c
+++ b/sys/kern/subr_xxx.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)subr_xxx.c	8.1 (Berkeley) 6/10/93
- * $Id$
+ * $Id: subr_xxx.c,v 1.3 1994/08/02 07:42:36 davidg Exp $
  */
 
 /*
@@ -43,6 +43,8 @@
 
 #include <machine/cpu.h>
 
+extern int enosys __P((void));
+
 /*
  * Unsupported device function (e.g. writing to read-only device).
  */
@@ -105,3 +107,79 @@ nullop()
 
 	return (0);
 }
+
+/*
+ * Specific `no' and `null' operations.
+ * XXX the general ones are bogus.
+ * XXX device functions may belong elsewhere.
+ */
+
+#include <sys/conf.h>
+
+int
+noreset(dummy)
+	int dummy;
+{
+
+	return (ENODEV);
+}
+
+int
+nommap(dev, offset, nprot)
+	dev_t dev;
+	int offset;
+	int nprot;
+{
+
+	/* Don't return ENODEV.  That would allow mapping address ENODEV! */
+	return (-1);
+}
+
+void
+nostrategy(bp)
+	struct buf *bp;
+{
+
+}
+
+/*
+ * XXX this is probably bogus.  Any device that uses it isn't checking the
+ * minor number.
+ */
+int
+nullopen(dev, flag, mode, p)
+	dev_t dev;
+	int flag;
+	int mode;
+	struct proc *p;
+{
+
+	return (0);
+}
+
+int
+nullclose(dev, flag, mode, p)
+	dev_t dev;
+	int flag;
+	int mode;
+	struct proc *p;
+{
+
+	return (0);
+}
+
+void
+nullstop(tp, rw)
+	struct tty *tp;
+	int rw;
+{
+
+}
+
+int
+nullreset(foo)
+	int foo;
+{
+
+	return (0);
+}
diff --git a/sys/kern/tty_cons.c b/sys/kern/tty_cons.c
index 7cddb5e..0b509594 100644
--- a/sys/kern/tty_cons.c
+++ b/sys/kern/tty_cons.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)cons.c	7.2 (Berkeley) 5/9/91
- *	$Id: cons.c,v 1.32 1995/09/09 18:09:44 davidg Exp $
+ *	$Id: cons.c,v 1.33 1995/09/10 18:57:25 bde Exp $
  */
 
 #include <sys/param.h>
@@ -53,7 +53,10 @@
 #include "vt.h"
 #include "sio.h"
 static struct consdev constab[] = {
-#if NSC > 0 || NVT > 0
+#if NSC > 0
+	{ sccnprobe,	sccninit,	sccngetc,	sccncheckc,	sccnputc },
+#endif
+#if NVT > 0
 	{ pccnprobe,	pccninit,	pccngetc,	pccncheckc,	pccnputc },
 #endif
 #if NSIO > 0
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index 66785b5..a198e8e 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)conf.h	8.3 (Berkeley) 1/21/94
- * $Id: conf.h,v 1.15 1995/05/30 08:14:14 rgrimes Exp $
+ * $Id: conf.h,v 1.16 1995/09/08 19:18:02 bde Exp $
  */
 
 #ifndef _SYS_CONF_H_
@@ -138,12 +138,28 @@ struct swdevt {
 #define sw_freed	sw_flags	/* XXX compat */
 
 #ifdef KERNEL
-extern int setdumpdev __P((dev_t));
+d_reset_t	noreset;
+d_mmap_t	nommap;
+d_strategy_t	nostrategy;
+
+d_open_t	nullopen;
+d_close_t	nullclose;
+d_stop_t	nullstop;
+d_reset_t	nullreset;
+/*
+ * XXX d_strategy seems to be unused for cdevs and called without checking
+ * for it being non-NULL for bdevs.
+ */
+#define	nullstrategy	((d_strategy *)NULL)
 
 dev_t	chrtoblk __P((dev_t dev));
+int	getmajorbyname __P((const char *name));
 int	isdisk __P((dev_t dev, int type));
 int	iskmemdev __P((dev_t dev));
 int	iszerodev __P((dev_t dev));
+int	register_cdev __P((const char *name, const struct cdevsw *cdp));
+int	setdumpdev __P((dev_t));
+int	unregister_cdev __P((const char *name, const struct cdevsw *cdp));
 #endif
 
 #endif /* !_SYS_CONF_H_ */
diff --git a/sys/sys/cons.h b/sys/sys/cons.h
index 35d919a..8fbd43f 100644
--- a/sys/sys/cons.h
+++ b/sys/sys/cons.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)cons.h	7.2 (Berkeley) 5/9/91
- *	$Id: cons.h,v 1.9 1995/04/24 16:43:01 bde Exp $
+ *	$Id: cons.h,v 1.10 1995/09/10 18:57:26 bde Exp $
  */
 
 #ifndef _MACHINE_CONS_H_
@@ -60,6 +60,12 @@ cn_getc_t	pccngetc;
 cn_checkc_t	pccncheckc;
 cn_putc_t	pccnputc;
 
+cn_probe_t	sccnprobe;
+cn_init_t	sccninit;
+cn_getc_t	sccngetc;
+cn_checkc_t	sccncheckc;
+cn_putc_t	sccnputc;
+
 cn_probe_t	siocnprobe;
 cn_init_t	siocninit;
 cn_getc_t	siocngetc;
diff --git a/sys/sys/linedisc.h b/sys/sys/linedisc.h
index 66785b5..a198e8e 100644
--- a/sys/sys/linedisc.h
+++ b/sys/sys/linedisc.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)conf.h	8.3 (Berkeley) 1/21/94
- * $Id: conf.h,v 1.15 1995/05/30 08:14:14 rgrimes Exp $
+ * $Id: conf.h,v 1.16 1995/09/08 19:18:02 bde Exp $
  */
 
 #ifndef _SYS_CONF_H_
@@ -138,12 +138,28 @@ struct swdevt {
 #define sw_freed	sw_flags	/* XXX compat */
 
 #ifdef KERNEL
-extern int setdumpdev __P((dev_t));
+d_reset_t	noreset;
+d_mmap_t	nommap;
+d_strategy_t	nostrategy;
+
+d_open_t	nullopen;
+d_close_t	nullclose;
+d_stop_t	nullstop;
+d_reset_t	nullreset;
+/*
+ * XXX d_strategy seems to be unused for cdevs and called without checking
+ * for it being non-NULL for bdevs.
+ */
+#define	nullstrategy	((d_strategy *)NULL)
 
 dev_t	chrtoblk __P((dev_t dev));
+int	getmajorbyname __P((const char *name));
 int	isdisk __P((dev_t dev, int type));
 int	iskmemdev __P((dev_t dev));
 int	iszerodev __P((dev_t dev));
+int	register_cdev __P((const char *name, const struct cdevsw *cdp));
+int	setdumpdev __P((dev_t));
+int	unregister_cdev __P((const char *name, const struct cdevsw *cdp));
 #endif
 
 #endif /* !_SYS_CONF_H_ */