2 files changed, 27 insertions(+), 1 deletions(-)

M pc/devvga.c
M pc/screen.h

@@ 17,10 17,14 @@
 enum {
 	Qdir,
 	Qvgactl,
+	Qvgaovl,
+	Qvgaovlctl,
 };
 
 static Dirtab vgadir[] = {
-	"vgactl",	{ Qvgactl, 0 },		0,	0660,
+	"vgactl",		{ Qvgactl, 0 },		0,	0660,
+	"vgaovl",		{ Qvgaovl, 0 },		0,	0660,
+	"vgaovlctl",	{ Qvgaovlctl, 0 },	0, 	0660,
 };
 
 static void


@@ 131,6 135,11 @@ vgaread(Chan* c, void* a, long n, vlong off)
 
 		return n;
 
+	case Qvgaovl:
+	case Qvgaovlctl:
+		error(Ebadusefd);
+		break;
+
 	default:
 		error(Egreg);
 		break;


@@ 337,11 346,14 @@ vgactl(char* a)
 	error(Ebadarg);
 }
 
+char Enooverlay[] = "No overlay support";
+
 static long
 vgawrite(Chan* c, void* a, long n, vlong off)
 {
 	char *p;
 	ulong offset = off;
+	VGAscr *scr;
 
 	switch(c->qid.path & ~CHDIR){
 


@@ 363,6 375,19 @@ vgawrite(Chan* c, void* a, long n, vlong off)
 		free(p);
 		return n;
 
+	case Qvgaovl:
+		scr = &vgascreen[0];
+		pprint("vgawrite: Qvgaovl %d (%s)\n", Qvgaovl, scr->dev->name);
+		return 0;
+
+	case Qvgaovlctl:
+		scr = &vgascreen[0];
+		if (scr->dev->ovlctl == nil) {
+			error(Enooverlay);
+			break;
+		}
+		return scr->dev->ovlctl(scr, a, n);
+
 	default:
 		error(Egreg);
 		break;

@@ 68,6 68,7 @@ struct VGAdev {
 	ulong	(*linear)(VGAscr*, int*, int*);
 	void	(*drawinit)(VGAscr*);
 	int	(*fill)(VGAscr*, Rectangle, ulong);
+	int	(*ovlctl)(VGAscr*, void*, int);
 };
 
 struct VGAcur {