1 files changed, 24 insertions, 4 deletions

diff --git a/sys/i386/i386/vm86.c b/sys/i386/i386/vm86.c
index 329128790be6..25da03aee658 100644
--- a/sys/i386/i386/vm86.c
+++ b/sys/i386/i386/vm86.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: vm86.c,v 1.15 1998/08/16 00:05:05 bde Exp $
+ *	$Id: vm86.c,v 1.16 1998/09/29 09:06:00 bde Exp $
  */
 
 #include "opt_vm86.h"
@@ -626,16 +626,36 @@ vm86_datacall(intnum, vmf, buffer, buflen, segment, offset)
 	int buflen;
 	u_short *segment, *offset;
 {
+	int ret, internb;
 	u_int page;
+	u_short off;
+#define MAX_DATA_SIZE 1024
+	static u_char mapped_to_page1[MAX_DATA_SIZE * 2];
+	static u_char *buf;
 
+	if (buflen < 0 || buflen > MAX_DATA_SIZE)
+		return(-1);
         page = (u_int)buffer & PG_FRAME;
         *offset = (u_int)buffer & PAGE_MASK;
-        if ((*offset + buflen) & PG_FRAME)
-		return (-1);				/* XXX fixme! */
+	if ((*offset + buflen) & PG_FRAME) {
+		if (buf == NULL) {
+			buf = mapped_to_page1;
+			off = (u_int)buf & PAGE_MASK;
+			if ((off + MAX_DATA_SIZE) & PG_FRAME)
+				buf += PAGE_SIZE - off;
+		}
+		page = (u_int)buf & PG_FRAME;
+		bcopy((void *)buffer, (void *)buf, (size_t)buflen);
+		internb = 1;
+	} else
+		internb = 0;
 	*segment = 0x100;
 	page = vtophys(page);
 	vmf->vmf_trapno = page | (intnum & PAGE_MASK);
-	return (vm86_bioscall(vmf));
+	ret = vm86_bioscall(vmf);
+	if (internb)
+		bcopy((void *)buf, (void *)buffer, (size_t)buflen);
+	return ret;
 }
 
 #if 0