Fix the function CD(): "Clear to the end of the screen".

- When the video BIOS is called to clear the region (x, y)-(79, 24)
  (by scrolling), the slashed region in Fig.1 is cleared.  CD() is
  supposed to clear the region shown in Fig.2.
        x                 x
    +-------+         +-------+
    |       |         |       |
   y|   ////|        y|   ////|
    |   ////|         |///////|
    |   ////|         |///////|
    +-------+         +-------+
      Fig.1             Fig.2

- Don't move the cursor during this operation.

1 files changed, 15 insertions, 4 deletions

diff --git a/sys/boot/i386/libi386/vidconsole.c b/sys/boot/i386/libi386/vidconsole.c
index a2d74a1..bfdb5c1 100644
--- a/sys/boot/i386/libi386/vidconsole.c
+++ b/sys/boot/i386/libi386/vidconsole.c
@@ -308,15 +308,26 @@ CD(void)
 {
 
     get_pos();
+    if (curx > 0) {
+	v86.ctl = 0;
+	v86.addr = 0x10;
+	v86.eax = 0x0600;
+	v86.ebx = (bg_c << 4) + fg_c;
+	v86.ecx = (cury << 8) + curx;
+	v86.edx = (cury << 8) + 79;
+	v86int();
+	if (++cury > 24) {
+	    end_term();
+	    return;
+	}
+    }
     v86.ctl = 0;
     v86.addr = 0x10;
     v86.eax = 0x0600;
     v86.ebx = (bg_c << 4) + fg_c;
-    v86.ecx = v86.edx;
-    v86.edx = 0x184f;
+    v86.ecx = (cury << 8) + 0;
+    v86.edx = (24 << 8) + 79;
     v86int();
-    curx = 0;
-    curs_move(curx, cury);
     end_term();
 }