grub_err_t rc;
/* Try to initialize video mode 1024 x 768 with direct RGB.  */
rc = grub_video_setup (1024, 768, GRUB_VIDEO_MODE_TYPE_RGB);
if (rc != GRUB_ERR_NONE)
{
  /* Fall back to standard VGA Index Color mode.  */
  rc = grub_video_setup (640, 480, GRUB_VIDEO_MODE_TYPE_INDEX);
  if (rc != GRUB_ERR_NONE)
  {
  /* Handle error.  */
  }
}

grub_uint32_t x, y, width, height;
grub_video_color_t color;
struct grub_font_glyph glyph;
grub_err_t rc;
/* Query existing viewport.  */
grub_video_get_viewport (&x, &y, &width, &height);
/* Fill background.  */
color = grub_video_map_color (GRUB_COLOR_BACKGROUND);
grub_video_fill_rect (color, 0, 0, width, height);
/* Setup console viewport.  */
grub_video_set_viewport (x + 10, y + 10, width - 20, height - 20);
grub_video_get_viewport (&x, &y, &width, &height);
color = grub_video_map_color (GRUB_COLOR_CONSOLE_BACKGROUND);
grub_video_fill_rect (color, 0, 0, width, height);
/* Draw text to viewport.  */
color = grub_video_map_color (GRUB_COLOR_CONSOLE_TEXT);
grub_font_get_glyph ('X', &glyph);
grub_video_blit_glyph (&glyph, color, 0, 0);