+/* we initialize the VGA graphic mode */
+static void vbe_update_vgaregs(VGACommonState *s)
+{
+ int h, shift_control;
+
+ if (!vbe_enabled(s)) {
+ /* vbe is turned off -- nothing to do */
+ return;
+ }
+
+ /* graphic mode + memory map 1 */
+ s->gr[VGA_GFX_MISC] = (s->gr[VGA_GFX_MISC] & ~0x0c) | 0x04 |
+ VGA_GR06_GRAPHICS_MODE;
+ s->cr[VGA_CRTC_MODE] |= 3; /* no CGA modes */
+ s->cr[VGA_CRTC_OFFSET] = s->vbe_line_offset >> 3;
+ /* width */
+ s->cr[VGA_CRTC_H_DISP] =
+ (s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1;
+ /* height (only meaningful if < 1024) */
+ h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1;
+ s->cr[VGA_CRTC_V_DISP_END] = h;
+ s->cr[VGA_CRTC_OVERFLOW] = (s->cr[VGA_CRTC_OVERFLOW] & ~0x42) |
+ ((h >> 7) & 0x02) | ((h >> 3) & 0x40);
+ /* line compare to 1023 */
+ s->cr[VGA_CRTC_LINE_COMPARE] = 0xff;
+ s->cr[VGA_CRTC_OVERFLOW] |= 0x10;
+ s->cr[VGA_CRTC_MAX_SCAN] |= 0x40;
+
+ if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) {
+ shift_control = 0;
+ s->sr[VGA_SEQ_CLOCK_MODE] &= ~8; /* no double line */
+ } else {
+ shift_control = 2;
+ /* set chain 4 mode */
+ s->sr[VGA_SEQ_MEMORY_MODE] |= VGA_SR04_CHN_4M;
+ /* activate all planes */
+ s->sr[VGA_SEQ_PLANE_WRITE] |= VGA_SR02_ALL_PLANES;
+ }
+ s->gr[VGA_GFX_MODE] = (s->gr[VGA_GFX_MODE] & ~0x60) |
+ (shift_control << 5);
+ s->cr[VGA_CRTC_MAX_SCAN] &= ~0x9f; /* no double scan */
+}
+