diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index df465fa21e52..cc934e16ed8e 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 @@ cpu_startup(udata)
 	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 1dd0fb99557a..51dd7f9b877d 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 $
  */
 
 /*
@@ -909,6 +909,22 @@ isa_strayintr(d)
 		    "too many stray irq %d's; not logging any more\n", 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 8619dc9eac21..8ab9c9c6950e 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 @@ ansi_put(scr_stat *scp, u_char *buf, int len)
 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 b09c57e8031d..e660ba7dfc37 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 4fc699a7c62d..474484dae6f5 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 7cddb5e1a235..0b509594c3b9 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 35d919ae5819..8fbd43f93002 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 df465fa21e52..cc934e16ed8e 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 @@ cpu_startup(udata)
 	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 1dd0fb99557a..51dd7f9b877d 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 $
  */
 
 /*
@@ -909,6 +909,22 @@ isa_strayintr(d)
 		    "too many stray irq %d's; not logging any more\n", 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 4e3c08c4a318..d201daec70a5 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 cdf307319911..dc91d4756677 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 7f0ad9ec11ef..d84942a3a771 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 945ee24ebb9c..fc7651758ef8 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 8619dc9eac21..8ab9c9c6950e 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 @@ ansi_put(scr_stat *scp, u_char *buf, int len)
 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 b09c57e8031d..e660ba7dfc37 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 8619dc9eac21..8ab9c9c6950e 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 @@ ansi_put(scr_stat *scp, u_char *buf, int len)
 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 b09c57e8031d..e660ba7dfc37 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 e866b8aaf908..b0a0817f22fb 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 7cddb5e1a235..0b509594c3b9 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 66785b5246e7..a198e8e0a1fc 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 35d919ae5819..8fbd43f93002 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 66785b5246e7..a198e8e0a1fc 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_ */