1 files changed, 13 insertions, 9 deletions

diff --git a/arch/x86/boot/video-vga.c b/arch/x86/boot/video-vga.c
index 5d4742ed4aa2..95d86ce0421c 100644
--- a/arch/x86/boot/video-vga.c
+++ b/arch/x86/boot/video-vga.c
@@ -129,41 +129,45 @@ u16 vga_crtc(void)
         return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4;
 }
 
-static void vga_set_480_scanlines(int end)
+static void vga_set_480_scanlines(int lines)
 {
-        u16 crtc;
-        u8  csel;
+        u16 crtc;               /* CRTC base address */
+        u8  csel;               /* CRTC miscellaneous output register */
+        u8  ovfw;               /* CRTC overflow register */
+        int end = lines-1;
 
         crtc = vga_crtc();
 
+        ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40);
+
         out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */
         out_idx(0x0b, crtc, 0x06); /* Vertical total */
-        out_idx(0x3e, crtc, 0x07); /* Vertical overflow */
+        out_idx(ovfw, crtc, 0x07); /* Vertical overflow */
         out_idx(0xea, crtc, 0x10); /* Vertical sync start */
-        out_idx(end, crtc, 0x12); /* Vertical display end */
+        out_idx(end,  crtc, 0x12); /* Vertical display end */
         out_idx(0xe7, crtc, 0x15); /* Vertical blank start */
         out_idx(0x04, crtc, 0x16); /* Vertical blank end */
         csel = inb(0x3cc);
         csel &= 0x0d;
         csel |= 0xe2;
-        outb(csel, 0x3cc);
+        outb(csel, 0x3c2);
 }
 
 static void vga_set_80x30(void)
 {
-        vga_set_480_scanlines(0xdf);
+        vga_set_480_scanlines(30*16);
 }
 
 static void vga_set_80x34(void)
 {
         vga_set_14font();
-        vga_set_480_scanlines(0xdb);
+        vga_set_480_scanlines(34*14);
 }
 
 static void vga_set_80x60(void)
 {
         vga_set_8font();
-        vga_set_480_scanlines(0xdf);
+        vga_set_480_scanlines(60*8);
 }
 
 static int vga_set_mode(struct mode_info *mode)