Index: include/video/davincifb.h
===================================================================
--- include/video/davincifb.h	(revision 765)
+++ include/video/davincifb.h	(working copy)
@@ -40,6 +40,21 @@
 	u_int32_t zoom_v;
 } zoom_params_t;
 
+
+typedef struct fb_set_start {
+	int		offset;		/* offset from smem_start */
+	unsigned long	physical;	/* absolute physical address when offset < 0 */
+
+	u_int64_t	sync;		/* input:  target sync counter for change or 0 for no sync at all,
+					   output: sync counter of actual change or 0 if still pending */
+} fb_set_start_t;
+
+
+#ifdef _IOC_TYPECHECK
+#undef _IOC_TYPECHECK
+#define _IOC_TYPECHECK(x)     (sizeof(x))
+#endif
+
 #define	RAM_CLUT_SIZE	256*3
 #define FBIO_ENABLE_DISABLE_WIN		\
 	_IOW('F', 0x30, unsigned char)
@@ -83,6 +98,8 @@
 	_IOW('F', 0x49, u_int32_t)
 #define FBIO_SET_CURSOR         	\
 	_IOW('F', 0x50, struct fb_cursor)
+#define FBIO_SET_START     		\
+	_IOW('F', 0x66, struct fb_set_start)
 
 /* 
  * Defines and Constants
Index: drivers/video/davincifb.c
===================================================================
--- drivers/video/davincifb.c	(revision 765)
+++ drivers/video/davincifb.c	(working copy)
@@ -1095,6 +1095,58 @@
 	return 0;
 }
 
+static int
+davincifb_set_start( struct fb_set_start *set, struct fb_info *info )
+{
+	struct vpbe_dm_win_info *win   = (struct vpbe_dm_win_info *) info->par;
+	unsigned long            start = 0;
+
+	/* Physical mode (absolute address)? */
+	if (set->offset < 0) {
+		start = set->physical;
+
+		/* FIXME: address checks */
+	}
+	else {
+		/* Offset mode (from frame buffer device base). */
+		if (set->offset + info->var.yres * info->fix.line_length >= win->fb_size)
+			return -EFAULT;
+
+		start = win->fb_base_phys + set->offset;
+	}
+
+	/* Set on explicit sync count? */
+	if (set->sync > 1) {
+		if (set->sync <= dm->vsync_cnt) {
+			set_sdram_params( info->fix.id, start, info->fix.line_length );
+			win->sdram_address = start;
+
+			set->sync = dm->vsync_cnt;
+		}
+		else {
+			/* FIXME: No queue yet. */
+			win->sdram_address = start;
+
+			set->sync = 0;
+		}
+	}
+	/* Set on next sync? */
+	else if (set->sync) {
+		win->sdram_address = start;
+
+		set->sync = 0;
+	}
+	/* Set now! */
+	else {
+		set_sdram_params( info->fix.id, start, info->fix.line_length );
+		win->sdram_address = start;
+
+		set->sync = dm->vsync_cnt;
+	}
+
+	return 0;
+}
+
 /*
  * davincifb_ioctl - handler for private ioctls.
  */
@@ -1105,6 +1157,7 @@
 	struct vpbe_dm_win_info *w = (struct vpbe_dm_win_info *)info->par;
 	void __user *argp = (void __user *)arg;
 	struct fb_fillrect rect;
+	struct fb_set_start set_start;
 	zoom_params_t zoom;
 	int retval = 0;
 	long std = 0;
@@ -1414,6 +1467,16 @@
 			return -EINVAL;
 		break;
 
+	case FBIO_SET_START:
+		if (copy_from_user(&set_start, argp, sizeof(set_start)))
+			return -EFAULT;
+		retval = davincifb_set_start( &set_start, &w->info );
+		if (retval)
+			return retval;
+		if (copy_to_user(argp, &set_start, sizeof(set_start)))
+			return -EFAULT;
+		break;
+
 	default:
 		retval = -EINVAL;
 		break;