[console] Add option to update margins and bg-image of vesa mode console

Adding --update to the console call will prevent the vesa mode from
being initialized again. The existing mode will be reused. This makes
it possible to quickly update the background image or console margins
without ugly flickering.

1 files changed, 41 insertions, 31 deletions

diff --git a/src/core/fbcon.c b/src/core/fbcon.c
index 44a56e105..f64bab7ce 100644
--- a/src/core/fbcon.c
+++ b/src/core/fbcon.c
@@ -520,6 +520,9 @@ static int fbcon_picture_init ( struct fbcon *fbcon,
 
 	/* Allocate buffer */
 	len = ( pixel->height * pixel->stride );
+	if ( picture->start ) {
+		ufree( picture->start );
+	}
 	picture->start = umalloc ( len );
 	if ( ! picture->start ) {
 		DBGC ( fbcon, "FBCON %p could not allocate %zd bytes for "
@@ -595,21 +598,23 @@ int fbcon_init ( struct fbcon *fbcon, userptr_t start,
 	unsigned int bottom;
 	int rc;
 
-	/* Initialise data structure */
-	memset ( fbcon, 0, sizeof ( *fbcon ) );
-	fbcon->start = start;
-	fbcon->pixel = pixel;
-	assert ( pixel->len <= sizeof ( uint32_t ) );
-	fbcon->map = map;
-	fbcon->font = font;
-	fbcon->ctx.handlers = fbcon_ansiesc_handlers;
-	fbcon->show_cursor = 1;
-
-	/* Derive overall length */
-	fbcon->len = ( pixel->height * pixel->stride );
-	DBGC ( fbcon, "FBCON %p at [%08lx,%08lx)\n", fbcon,
-	       user_to_phys ( fbcon->start, 0 ),
-	       user_to_phys ( fbcon->start, fbcon->len ) );
+	if ( ! config->lazy_update ) {
+		/* Initialise data structure */
+		memset ( fbcon, 0, sizeof ( *fbcon ) );
+		fbcon->start = start;
+		fbcon->pixel = pixel;
+		assert ( pixel->len <= sizeof ( uint32_t ) );
+		fbcon->map = map;
+		fbcon->font = font;
+		fbcon->ctx.handlers = fbcon_ansiesc_handlers;
+		fbcon->show_cursor = 1;
+
+		/* Derive overall length */
+		fbcon->len = ( pixel->height * pixel->stride );
+		DBGC ( fbcon, "FBCON %p at [%08lx,%08lx)\n", fbcon,
+				 user_to_phys ( fbcon->start, 0 ),
+				 user_to_phys ( fbcon->start, fbcon->len ) );
+	}
 
 	/* Calculate margin.  If the actual screen size is larger than
 	 * the requested screen size, then update the margins so that
@@ -664,27 +669,32 @@ int fbcon_init ( struct fbcon *fbcon, userptr_t start,
 	       fbcon->margin.top,
 	       ( fbcon->pixel->height - fbcon->margin.bottom ) );
 
-	/* Set default colours */
-	fbcon_set_default_foreground ( fbcon );
-	fbcon_set_default_background ( fbcon );
+	if ( ! config->lazy_update ) {
+		/* Set default colours */
+		fbcon_set_default_foreground ( fbcon );
+		fbcon_set_default_background ( fbcon );
+
+		/* Allocate and initialise stored character array */
+		fbcon->text.start = umalloc ( fbcon->character.width *
+							fbcon->character.height *
+							sizeof ( struct fbcon_text_cell ) );
+		if ( ! fbcon->text.start ) {
+			rc = -ENOMEM;
+			goto err_text;
+		}
+		fbcon_clear ( fbcon, 0 );
 
-	/* Allocate and initialise stored character array */
-	fbcon->text.start = umalloc ( fbcon->character.width *
-				      fbcon->character.height *
-				      sizeof ( struct fbcon_text_cell ) );
-	if ( ! fbcon->text.start ) {
-		rc = -ENOMEM;
-		goto err_text;
+		/* Set framebuffer to all black (including margins) */
+		memset_user ( fbcon->start, 0, 0, fbcon->len );
+	} else {
+		fbcon_clear ( fbcon, 0 );
 	}
-	fbcon_clear ( fbcon, 0 );
-
-	/* Set framebuffer to all black (including margins) */
-	memset_user ( fbcon->start, 0, 0, fbcon->len );
 
 	/* Generate pixel buffer from background image, if applicable */
 	if ( config->pixbuf &&
-	     ( ( rc = fbcon_picture_init ( fbcon, config->pixbuf ) ) != 0 ) )
-		goto err_picture;
+	     ( ( rc = fbcon_picture_init ( fbcon, config->pixbuf ) ) != 0 ) &&
+		  ( ! config->lazy_update ) )
+		goto err_picture; /* Keep going w/o background in lazy_update mode */
 
 	/* Draw background picture (including margins), if applicable */
 	if ( fbcon->picture.start ) {