Fix initialization of video_mode_ptr. It only worked if the segments

in the far pointers are multiples of 4K (as is normal when the video
BIOS is at seg 0xc000).  Disallow mode switching if the pointer is bad.

Use a new pa_to_va() macro for all BIOS and video addresses in syscons.

1 files changed, 32 insertions, 9 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 3b4f619..d8e5f34 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -35,7 +35,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: syscons.c,v 1.71 1994/10/23 21:27:36 wollman Exp $
+ *	$Id: syscons.c,v 1.72 1994/10/24 21:36:38 wollman Exp $
  */
 
 #include "sc.h"
@@ -57,6 +57,7 @@
 #include <sys/malloc.h>
 #include <sys/devconf.h>
 
+#include <machine/clock.h>
 #include <machine/console.h>
 #include <machine/psl.h>
 #include <machine/frame.h>
@@ -76,6 +77,12 @@
 #include <i386/isa/iso8859.font>
 #endif
 
+/* vm things */
+#define	ISMAPPED(pa, width) \
+	(((pa) <= (u_long)0x1000 - (width)) \
+	 || ((pa) >= 0xa0000 && (pa) <= 0x100000 - (width)))
+#define	pa_to_va(pa)	(KERNBASE + (pa))	/* works if ISMAPPED(pa...) */
+
 /* status flags */
 #define LOCK_KEY_MASK	0x0000F
 #define LED_MASK	0x00007
@@ -200,6 +207,7 @@ static	int		scrn_blanked = 0;	/* screen saver active flag */
 static	int		scrn_saver = 0;		/* screen saver routine */
 static	long 		scrn_time_stamp;
 static  u_char		scr_map[256];
+static	char 		*video_mode_ptr = NULL;
 
 /* function prototypes */
 int pcprobe(struct isa_device *dev);
@@ -281,11 +289,10 @@ struct	tty 		*pccons[NCONS+1];
 struct	tty 		pccons[NCONS+1];
 #endif
 #define	timeout_t	timeout_func_t
-#define	MONO_BUF	(KERNBASE+0xB0000)
-#define	CGA_BUF		(KERNBASE+0xB8000)
+#define	MONO_BUF	pa_to_va(0xB0000)
+#define	CGA_BUF		pa_to_va(0xB8000)
 u_short			*Crtat = (u_short *)MONO_BUF;
 void 	consinit(void) 	{scinit();}
-extern  char 		*video_mode_ptr;
 
 struct	isa_driver scdriver = {
 	pcprobe, pcattach, "sc", 1
@@ -666,7 +673,7 @@ pcioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
         case SW_ENH_B80x25: case SW_ENH_C80x25:
         case SW_ENH_B80x43: case SW_ENH_C80x43:
 
-        	if (!crtc_vga)
+        	if (!crtc_vga || video_mode_ptr == NULL)
         		return ENXIO;
 		cmd &= 0xFF;
 		i = cmd < M_VGA_C80x50 ?
@@ -2107,7 +2114,23 @@ scinit(void)
 	/* is this a VGA or higher ? */
 	outb(crtc_addr, 7);
 	if (inb(crtc_addr) == 7) {
+		u_long	pa;
+		u_long	segoff;
+
 		crtc_vga = 1;
+
+		/*
+		 * Get the BIOS video mode pointer.
+		 */
+		segoff = *(u_long *)pa_to_va(0x4a8);
+		pa = (((segoff & 0xffff0000) >> 12) + (segoff & 0xffff));
+		if (ISMAPPED(pa, sizeof(u_long))) {
+			segoff = *(u_long *)pa_to_va(pa);
+			pa = (((segoff & 0xffff0000) >> 12)
+			      + (segoff & 0xffff));
+			if (ISMAPPED(pa, 64))
+				video_mode_ptr = (char *)pa_to_va(pa);
+		}
 #if defined(FAT_CURSOR)
                 start = 0;
                 end = 18;
@@ -2639,7 +2662,7 @@ set_mode(scr_stat *scp)
 		return;
 
 	/* mode change only on VGA's */
-	if (!crtc_vga) {
+	if (!crtc_vga || video_mode_ptr == NULL) {
 		/* (re)activate cursor */
 		untimeout((timeout_t)cursor_pos, 0);
 		cursor_pos(1);
@@ -2685,7 +2708,7 @@ set_mode(scr_stat *scp)
        	case M_ENH_B40x25: case M_ENH_C40x25: 
        	case M_ENH_B80x25: case M_ENH_C80x25:
 
-		modetable = (char*)(video_mode_ptr + (scp->mode * 64));
+		modetable = video_mode_ptr + (scp->mode * 64);
 setup_mode:
 		set_vgaregs(modetable);
 		font_size = *(modetable + 2);
@@ -2799,11 +2822,11 @@ copy_font(int direction, int segment, int size, char* font)
     	for (ch=0; ch < 256; ch++) 
 	    for (line=0; line < size; line++) 
 		if (direction)
-		    *((char *)atdevbase+(segment*0x4000)+(ch*32)+line) = 
+		    *(char *)pa_to_va(VIDEOMEM+(segment*0x4000)+(ch*32)+line) =
 					font[(ch*size)+line];	
 		else
 		    font[(ch*size)+line] =
-		    *((char *)atdevbase+(segment*0x4000)+(ch*32)+line);
+		    *(char *)pa_to_va(VIDEOMEM+(segment*0x4000)+(ch*32)+line);
 	/* setup vga for text mode again */
 	s = splhigh();
 	inb(crtc_addr+6);				/* reset flip/flop */