fix writing garbage cursor image in main by removing
the code. the kernel gc drivers will load the arrow
image when initialized so there is no need to touch it.

the vesa modeinfo dx field is the visual width of
the framebuffer image and is not always equal to the
width of the framebuffer memory image. account for this
by setting vga->virtx in the options phase when needed.

filter out modes in vbemodeinfo that are not supported
by plan9 devdraw (text, planar, non chain, yuv, stereo).

filter out modes that say they are not supported by the
hardware, dont support linear framebuffer or being non
graphics modes.

renamed the Vmode.name field to Vmode.size as thats what
it really is. fill in standard vesa timing information
in dbvesamode().

some other minjor fixes in vesa.c

Reference: /n/sources/patch/maybe/vga-vesa-modes
Date: Wed Mar 16 01:34:55 CET 2011
Signed-off-by: cinap_lenrek@gmx.de

--- /sys/src/cmd/aux/vga/main.c	Wed Mar 16 01:21:02 2011
+++ /sys/src/cmd/aux/vga/main.c	Wed Mar 16 01:20:59 2011
@@ -158,7 +158,7 @@
 {
 	char *bios, buf[256], sizeb[256], *p, *vsize, *psize;
 	char *type, *vtype;
-	int fd, virtual, len;
+	int virtual, len;
 	Ctlr *ctlr;
 	Vga *vga;
 
@@ -454,12 +454,6 @@
 				vgactlw("hwgc", "soft");
 			else
 				vgactlw("hwgc", vga->hwgc->name);
-
-			/* might as well initialize the cursor */
-			if((fd = open("/dev/cursor", OWRITE)) >= 0){
-				write(fd, buf, 0);
-				close(fd);
-			}
 
 			if(vga->virtx != vga->mode->x || vga->virty != vga->mode->y){
 				sprint(buf, "%dx%d", vga->mode->x, vga->mode->y);
--- /sys/src/cmd/aux/vga/vesa.c	Wed Mar 16 01:21:09 2011
+++ /sys/src/cmd/aux/vga/vesa.c	Wed Mar 16 02:13:25 2011
@@ -31,8 +31,8 @@
 
 struct Vmode
 {
-	char	name[32];
-	char	chan[32];
+	char	size[Namelen+1];
+	char	chan[Namelen+1];
 	int	id;
 	int	attr;	/* flags */
 	int	bpl;
@@ -89,7 +89,9 @@
 #define PLONG(p, v) (p)[0] = (v); (p)[1] = (v)>>8; (p)[2] = (v)>>16; (p)[3] = (v)>>24
 
 static Vbe *vbe;
-static Edid edid;
+static Edid *edid;
+
+extern Mode *vesamodes[];
 
 Vbe *mkvbe(void);
 int vbecheck(Vbe*);
@@ -116,6 +118,7 @@
 		fprint(2, "dbvesa: %r\n");
 		return 0;
 	}
+
 	vga->link = alloc(sizeof(Ctlr));
 	*vga->link = vesa;
 	vga->vesa = vga->link;
@@ -129,32 +132,38 @@
 }
 
 Mode*
-dbvesamode(char *mode)
+dbvesamode(char *size)
 {
-	int i;
+	int i, width;
 	uchar *p, *ep;
+	Attr *a;
 	Vmode vm;
 	Mode *m;
+	Modelist *l;
 	
 	if(vbe == nil)
 		return nil;
 
-	p = vbemodes(vbe);
-	if(p == nil)
-		return nil;
-	for(ep=p+1024; (p[0]!=0xFF || p[1]!=0xFF) && p<ep; p+=2){
-		if(vbemodeinfo(vbe, WORD(p), &vm) < 0)
-			continue;
-		if(strcmp(vm.name, mode) == 0)
+	if(strncmp(size, "0x", 2) == 0){
+		if(vbemodeinfo(vbe, strtol(size+2, nil, 16), &vm) == 0)
 			goto havemode;
-	}
-	if(1){
-		fprint(2, "warning: scanning for unoffered vesa modes\n");
-		for(i=0x100; i<0x200; i++){
-			if(vbemodeinfo(vbe, i, &vm) < 0)
-				continue;
-			if(strcmp(vm.name, mode) == 0)
-				goto havemode;
+	}else{
+		if(p = vbemodes(vbe)){
+			for(ep=p+1024; (p[0]!=0xFF || p[1]!=0xFF) && p<ep; p+=2){
+				if(vbemodeinfo(vbe, WORD(p), &vm) < 0)
+					continue;
+				if(strcmp(vm.size, size) == 0)
+					goto havemode;
+			}
+		}
+		if(1){
+			fprint(2, "warning: scanning for unoffered vesa modes\n");
+			for(i=0x100; i<0x200; i++){
+				if(vbemodeinfo(vbe, i, &vm) < 0)
+					continue;
+				if(strcmp(vm.size, size) == 0)
+					goto havemode;
+			}
 		}
 	}
 	werrstr("no such vesa mode");
@@ -162,13 +171,8 @@
 
 havemode:
 	m = alloc(sizeof(Mode));
-	strcpy(m->type, "vesa");
-	strcpy(m->size, vm.name);
-	strcpy(m->chan, vm.chan);
-	m->frequency = 100;
 	m->x = vm.dx;
 	m->y = vm.dy;
-	m->z = vm.depth;
 	m->ht = m->x;
 	m->shb = m->x;
 	m->ehb = m->x;
@@ -177,11 +181,49 @@
 	m->vt = m->y;
 	m->vrs = m->y;
 	m->vre = m->y;
+	m->frequency = m->ht * m->vt * 60;
+
+	/* get default monitor timing */
+	for(i=0; vesamodes[i]; i++){
+		if(vesamodes[i]->x != vm.dx || vesamodes[i]->y != vm.dy)
+			continue;
+		*m = *vesamodes[i];
+		break;
+	}
+	if(edid){
+		for(l = edid->modelist; l; l = l->next){
+			if(l->x != vm.dx || l->y != vm.dy)
+				continue;
+			*m = *((Mode*)l);
+			break;
+		}
+	}
+
+	strcpy(m->type, "vesa");
+	strcpy(m->size, vm.size);
+	strcpy(m->chan, vm.chan);
+	m->z = vm.depth;
+
+	a = alloc(sizeof(Attr));
+	a->attr = "id";
+	a->val = alloc(32);
+	sprint(a->val, "0x%x", vm.id);
+
+	a->next = nil;
+	m->attr = a;
+
+	/* account for framebuffer stride */
+	width = vm.bpl * 8 / m->z;
+	if(width > m->x){
+		a = alloc(sizeof(Attr));
+		a->attr = "virtx";
+		a->val = alloc(32);
+		sprint(a->val, "%d", width);
+
+		a->next = m->attr;
+		m->attr = a;
+	}
 
-	m->attr = alloc(sizeof(Attr));
-	m->attr->attr = "id";
-	m->attr->val = alloc(32);
-	sprint(m->attr->val, "0x%x", vm.id);
 	return m;
 }
 
@@ -194,7 +236,20 @@
 		vga->vesa = ctlr;
 	vbesnarf(vbe, vga);
 	vga->linear = 1;
-	ctlr->flag |= Hlinear|Ulinear;
+	ctlr->flag |= Hlinear|Ulinear|Fsnarf;
+}
+
+static void
+options(Vga *vga, Ctlr *ctlr)
+{
+	char *v;
+
+	if(v = dbattr(vga->mode->attr, "virtx")){
+		vga->virtx = atoi(v);
+		vga->virty = vga->mode->y;
+		vga->panning = 0;
+	}
+	ctlr->flag |= Foptions;
 }
 
 static void
@@ -233,18 +288,14 @@
 	for(i=0x100; i<0x1FF; i++)
 		if(!did[i])
 			vbeprintmodeinfo(vbe, i, " (unoffered)");
-				
-	
-	if(vbeddcedid(vbe, &edid) < 0)
-		fprint(2, "warning: reading edid: %r\n");
-	else
-		printedid(&edid);
+	if(edid)
+		printedid(edid);
 }
 
 Ctlr vesa = {
 	"vesa",			/* name */
 	snarf,				/* snarf */
-	0,			/* options */
+	options,			/* options */
 	0,				/* init */
 	load,				/* load */
 	dump,				/* dump */
@@ -273,19 +324,34 @@
 	0
 };
 
+enum {
+	AttrSupported	= 1<<0,
+	AttrTTY		= 1<<2,
+	AttrColor	= 1<<3,
+	AttrGraphics	= 1<<4,
+	AttrNotVGA	= 1<<5,
+	AttrNotWinVGA	= 1<<6,
+	AttrLinear	= 1<<7,
+	AttrDoublescan	= 1<<8,
+	AttrInterlace	= 1<<9,
+	AttrTriplebuf	= 1<<10,
+	AttrStereo	= 1<<11,
+	AttrDualAddr	= 1<<12,
+};
+
 static Flag modeattributesflags[] = {
-	1<<0, "supported",
-	1<<2, "tty",
-	1<<3, "color",
-	1<<4, "graphics",
-	1<<5, "not-vga",
-	1<<6, "no-windowed-vga",
-	1<<7, "linear",
-	1<<8, "double-scan",
-	1<<9, "interlace",
-	1<<10, "triple-buffer",
-	1<<11, "stereoscopic",
-	1<<12, "dual-start-addr",
+	AttrSupported,	"supported",
+	AttrTTY,	"tty",
+	AttrColor,	"color",
+	AttrGraphics,	"graphics",
+	AttrNotVGA,	"not-vga",
+	AttrNotWinVGA,	"no-windowed-vga",
+	AttrLinear,	"linear",
+	AttrDoublescan,	"double-scan",
+	AttrInterlace,	"interlace",
+	AttrTriplebuf,	"triple-buffer",
+	AttrStereo,	"stereoscopic",
+	AttrDualAddr,	"dual-start-addr",
 	0
 };
 
@@ -302,10 +368,29 @@
 	0
 };
 
+enum {
+	ModText = 0,
+	ModCGA,
+	ModHercules,
+	ModPlanar,
+	ModPacked,
+	ModNonChain4,
+	ModDirect,
+	ModYUV,
+};
+
 static char *modelstr[] = {
-	"text", "cga", "hercules", "planar", "packed", "non-chain4", "direct", "YUV"
+	[ModText]	"text",
+	[ModCGA]	"cga",
+	[ModHercules]	"hercules",
+	[ModPlanar]	"planar",
+	[ModPacked]	"packed",
+	[ModNonChain4]	"non-chain4",
+	[ModDirect]	"direct",
+	[ModYUV]	"YUV",
 };
 
+
 static void
 printflags(Flag *f, int b)
 {
@@ -402,8 +487,12 @@
 	strcpy((char*)p, "VBE2");
 	if(vbecall(vbe, &u) < 0)
 		return -1;
-	if(memcmp(p, "VESA", 4) != 0 || p[5] < 2){
-		werrstr("invalid vesa signature %.4H %.4H\n", p, p+4);
+	if(memcmp(p, "VESA", 4)){
+		werrstr("invalid vesa signature %.4H\n", p);
+		return -1;
+	}
+	if(p[5] < 2){
+		werrstr("invalid vesa version: %.4H\n", p+4);
 		return -1;
 	}
 	return 0;
@@ -422,6 +511,13 @@
 	if(memcmp(p, "VESA", 4) != 0 || p[5] < 2)
 		return -1;
 	vga->apz = WORD(p+18)*0x10000UL;
+	if(edid == nil){
+		edid = alloc(sizeof(Edid));
+		if(vbeddcedid(vbe, edid) < 0){
+			free(edid);
+			edid = nil;
+		}
+	}
 	return 0;
 }
 
@@ -474,11 +570,9 @@
 int
 vbemodeinfo(Vbe *vbe, int id, Vmode *m)
 {
-	int o;
-	ulong d, c, x;
 	uchar *p;
-	char tmp[sizeof m->chan];
 	Ureg u;
+	int mod;
 
 	p = vbesetup(vbe, &u, 0x4F01);
 	u.cx = id;
@@ -487,11 +581,31 @@
 
 	m->id = id;
 	m->attr = WORD(p);
+	if(!(m->attr & AttrSupported))
+		goto Unsupported;
+	if(!(m->attr & AttrGraphics))
+		goto Unsupported;
+	if(!(m->attr & AttrLinear))
+		goto Unsupported;
 	m->bpl = WORD(p+16);
 	m->dx = WORD(p+18);
 	m->dy = WORD(p+20);
 	m->depth = p[25];
-	m->model = p[27] < nelem(modelstr) ? modelstr[p[27]] : "unknown";
+	if((m->dx * m->dy * m->depth) <= 0)
+		goto Unsupported;
+	mod = p[27];
+	switch(mod){
+	default:
+	Unsupported:
+		werrstr("mode unsupported");
+		return -1;
+	case ModCGA:
+	case ModHercules:
+	case ModPacked:
+	case ModDirect:
+		m->model = modelstr[mod];
+		break;
+	}
 	m->r = p[31];
 	m->g = p[33];
 	m->b = p[35];
@@ -502,44 +616,49 @@
 	m->xo = p[38];
 	m->directcolor = p[39];
 	m->paddr = LONG(p+40);
-	snprint(m->name, sizeof m->name, "%dx%dx%d",
-		m->dx, m->dy, m->depth);
-	if(m->depth <= 8) {
-		snprint(m->chan, sizeof m->chan, "m%d", m->depth);
-		return 0;
-	}
 
-	m->xo = m->x = 0;
-	d = 1 << (m->depth - 1);
-	d |= d - 1;
-	c  = ((1<<m->r)-1) << m->ro;
-	c |= ((1<<m->g)-1) << m->go;
-	c |= ((1<<m->b)-1) << m->bo;
-	x = d ^ c;
-	if(x != 0){
-		for(; (x & 1) == 0; x >>= 1)
-			m->xo++;
-		for(; x & 1; x >>= 1)
-			m->x++;
-	}
-
-	m->chan[0] = o = 0;
-	while(o < m->depth){
-		if(m->r && m->ro == o){
-			snprint(tmp, sizeof tmp, "r%d%s", m->r, m->chan);
-			o += m->r;
-		}else if(m->g && m->go == o){
-			snprint(tmp, sizeof tmp, "g%d%s", m->g, m->chan);
-			o += m->g;
-		}else if(m->b && m->bo == o){
-			snprint(tmp, sizeof tmp, "b%d%s", m->b, m->chan);
-			o += m->b;
-		}else if(m->x && m->xo == o){
-			snprint(tmp, sizeof tmp, "x%d%s", m->x, m->chan);
-			o += m->x;
-		}else
-			break;
-		strncpy(m->chan, tmp, sizeof m->chan);
+	snprint(m->size, sizeof m->size, "%dx%dx%d", m->dx, m->dy, m->depth);
+	if(m->depth <= 8)
+		snprint(m->chan, sizeof m->chan, "%c%d", 
+			(m->attr & AttrColor) ? 'm' : 'k', m->depth);
+	else {
+		int o;
+		ulong d, c, x;
+
+		m->xo = m->x = 0;
+		d = 1<<m->depth-1;
+		d |= d-1;
+		c = ((1<<m->r)-1) << m->ro;
+		c |= ((1<<m->g)-1) << m->go;
+		c |= ((1<<m->b)-1) << m->bo;
+		if(x = d ^ c){
+			for(; (x & 1) == 0; x >>= 1)
+				m->xo++;
+			for(; (x & 1) == 1; x >>= 1)
+				m->x++;
+		}
+
+		o = 0;
+		m->chan[0] = 0;
+		while(o < m->depth){
+			char tmp[sizeof m->chan];
+
+			if(m->r && m->ro == o){
+				snprint(tmp, sizeof tmp, "r%d%s", m->r, m->chan);
+				o += m->r;
+			}else if(m->g && m->go == o){
+				snprint(tmp, sizeof tmp, "g%d%s", m->g, m->chan);
+				o += m->g;
+			}else if(m->b && m->bo == o){
+				snprint(tmp, sizeof tmp, "b%d%s", m->b, m->chan);
+				o += m->b;
+			}else if(m->x && m->xo == o){
+				snprint(tmp, sizeof tmp, "x%d%s", m->x, m->chan);
+				o += m->x;
+			}else
+				break;
+			strncpy(m->chan, tmp, sizeof m->chan);
+		}
 	}
 	return 0;
 }
@@ -549,13 +668,11 @@
 {
 	Vmode m;
 
-	if(vbemodeinfo(vbe, id, &m) < 0){
-	//	Bprint(&stdout, "vesa: cannot get mode 0x%ux: %r\n", id);
+	if(vbemodeinfo(vbe, id, &m) < 0)
 		return;
-	}
 	printitem("vesa", "mode");
 	Bprint(&stdout, "0x%ux %s %s %s%s\n",
-		m.id, m.name, m.chan, m.model, suffix);
+		m.id, m.size, m.chan, m.model, suffix);
 }
 
 int
@@ -572,33 +689,12 @@
 int
 vbesetmode(Vbe *vbe, int id)
 {
-	uchar *p;
 	Ureg u;
 
-	p = vbesetup(vbe, &u, 0x4F02);
-	if(id != 3)
-		id |= 3<<14;	/* graphics: use linear, do not clear */
+	vbesetup(vbe, &u, 0x4F02);
 	u.bx = id;
-	USED(p);
-	/*
-	 * can set mode specifics (ht hss hse vt vss vse 0 clockhz refreshhz):
-	 *
-		u.bx |= 1<<11;
-		n = atoi(argv[2]); PWORD(p, n); p+=2;
-		n = atoi(argv[3]); PWORD(p, n); p+=2;
-		n = atoi(argv[4]); PWORD(p, n); p+=2;
-		n = atoi(argv[5]); PWORD(p, n); p+=2;
-		n = atoi(argv[6]); PWORD(p, n); p+=2;
-		n = atoi(argv[7]); PWORD(p, n); p+=2;
-		*p++ = atoi(argv[8]);
-		n = atoi(argv[9]); PLONG(p, n); p += 4;
-		n = atoi(argv[10]); PWORD(p, n); p += 2;
-		if(p != vbe.buf+19){
-			fprint(2, "prog error\n");
-			return;
-		}
-	 *
-	 */
+	if(id != 3)
+		u.bx |= 3<<14;	/* graphics: use linear, do not clear */
 	return vbecall(vbe, &u);
 }
 
@@ -679,8 +775,16 @@
 	
 	for(l=e->modelist; l; l=l->next){
 		printitem("edid", l->name);
-		Bprint(&stdout, "\n\t\tclock=%g\n\t\tshb=%d ehb=%d ht=%d\n\t\tvrs=%d vre=%d vt=%d\n\t\thsync=%c vsync=%c %s\n",
-			l->frequency/1.e6, l->shb, l->ehb, l->ht, l->vrs, l->vre, l->vt, l->hsync?l->hsync:'?', l->vsync?l->vsync:'?', l->interlace?"interlace=v" : "");
+		Bprint(&stdout, "\n\t\tclock=%g\n"
+			"\t\tshb=%d ehb=%d ht=%d\n"
+			"\t\tvrs=%d vre=%d vt=%d\n"
+			"\t\thsync=%c vsync=%c %s\n",
+			l->frequency/1.e6, 
+			l->shb, l->ehb, l->ht,
+			l->vrs, l->vre, l->vt,
+			l->hsync?l->hsync:'?',
+			l->vsync?l->vsync:'?',
+			l->interlace?"interlace=v" : "");
 	}
 }
 
@@ -690,9 +794,8 @@
 	int rr;
 	Modelist **lp;
 
-//m.z = 8; // BUG
 	rr = (m.frequency+m.ht*m.vt/2)/(m.ht*m.vt);
-	snprint(m.name, sizeof m.name, "%dx%dx%d@%dHz", m.x, m.y, m.z, rr);
+	snprint(m.name, sizeof m.name, "%dx%d@%dHz", m.x, m.y, rr);
 
 	if(m.shs == 0)
 		m.shs = m.shb;
@@ -831,8 +934,6 @@
 
 	return 0;
 }
-
-extern Mode *vesamodes[];
 
 int
 vesalookup(Mode *m, char *name)