Index: vbe.c
===================================================================
RCS file: /sources/vgabios/vgabios/vbe.c,v
retrieving revision 1.64
diff -u -r1.64 vbe.c
--- vbe.c	19 Jul 2011 18:25:05 -0000	1.64
+++ vbe.c	26 Jun 2013 02:21:07 -0000
@@ -754,6 +754,29 @@
   ret
 ASM_END
 
+ASM_START
+_size64:
+  push bp
+  mov  bp, sp
+  push dx
+
+; multiply bbp by yres first as results fit in 16bits
+; then multiply by xres
+  mov  ax, 8[bp]
+  mul  word 6[bp]
+  mul  word 4[bp]
+; divide by 2^19 ceiling result
+  add  ax, #0xffff
+  adc  dx, #7
+  mov  ax, dx
+  shr  ax, #3
+
+  pop  dx
+  pop  bp
+  ret
+ASM_END
+
+
 /** Function 00h - Return VBE Controller Information
  * 
  * Input:
@@ -857,7 +880,7 @@
 
         do
         {
-                size_64k = (Bit16u)((Bit32u)cur_info->info.XResolution * cur_info->info.XResolution * cur_info->info.BitsPerPixel) >> 19;
+                Bit16u size_64k = size64(cur_info->info.XResolution, cur_info->info.YResolution, cur_info->info.BitsPerPixel);
 
                 if ((cur_info->info.XResolution <= dispi_get_max_xres()) &&
                     (cur_info->info.BitsPerPixel <= dispi_get_max_bpp()) &&
@@ -917,14 +940,25 @@
 
         if (cur_info != 0)
         {
+                Bit16u max_bpp = dispi_get_max_bpp();
+                Bit16u size_64k;
+                Bit16u totalMemory;
+
+                outw(VBE_DISPI_IOPORT_INDEX, VBE_DISPI_INDEX_VIDEO_MEMORY_64K);
+                totalMemory = inw(VBE_DISPI_IOPORT_DATA);
 #ifdef DEBUG
                 printf("VBE found mode %x\n",CX);
 #endif
                 memsetb(ss, &info, 0, sizeof(ModeInfoBlock));
                 memcpyb(ss, &info, 0xc000, &(cur_info->info), sizeof(ModeInfoBlockCompact));
-                if (using_lfb) {
-                  info.NumberOfBanks = 1;
-                }
+                size_64k = size64(info.XResolution, info.YResolution, info.BitsPerPixel);
+                if ((info.XResolution > dispi_get_max_xres()) ||
+                    (info.BitsPerPixel > max_bpp) ||
+                    (size_64k > totalMemory))
+                  info.ModeAttributes &= ~VBE_MODE_ATTRIBUTE_SUPPORTED;
+
+                 /* Windows 8 require this to be 1! */
+                info.NumberOfBanks = 1;
 #ifdef PCI_VID
                 lfb_addr = pci_get_lfb_addr(PCI_VID);
 #else