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.

2 files changed, 61 insertions, 30 deletions

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);