support 512e drives.

- capacity now automaticly uses capacity16 if there are too
many sectors to be properly represented by capacity10.

- capacity16 now recoginzes 512e extensions and prints the
physical geometry as well as the logical geometry and the
first aligned sector.  e.g.

block size: 512
capacity
 7814037167 512 (976754645 4096 physical, first aligned sec 0)
ok 32

Reference: /n/atom/patch/applied2013/scuzz512e
Date: Thu Nov 14 17:54:47 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/scuzz/scuzz.c	Thu Nov 14 17:51:12 2013
+++ /sys/src/cmd/scuzz/scuzz.c	Thu Nov 14 17:51:12 2013
@@ -1378,37 +1378,47 @@
 }
 
 static long
-capacity(ScsiReq *rp, int nbyte)
+capacity16(ScsiReq *rp, int, char **)
 {
 	uchar d[32];
-	long n, r;
+	long n, r, l2p, align;
 	uvlong i;
 
-	if(nbyte == 16){
-		if((r = SRrcapacity16(rp, d)) == -1)
-			return -1;
-		i = GETBEVL(d);
-		n = GETBELONG(d + 8);
-	}else{
-		if((r = SRrcapacity(rp, d)) == -1)
-			return -1;
-		i = GETBELONG(d);
-		n = GETBELONG(d + 4);
-	}
-	Bprint(&bout, " %llud %lud\n", i, n);
+	if((r = SRrcapacity16(rp, d)) == -1)
+		return -1;
+	i = GETBEVL(d);
+	n = GETBELONG(d + 8);
+	l2p = d[13] & 7;
+	if(l2p != 0){
+		align = GETBE16(d+14) & 0x3fff;
+		Bprint(&bout, " %llud %lud (%llud %lud physical, first aligned sec %ld)\n",
+			i, n, i>>l2p, n<<l2p, align);
+	}else
+		Bprint(&bout, " %llud %lud\n", i, n);
 	return r;
 }
 
 static long
-cmdcapacity(ScsiReq *rp, int, char **)
+cmdcapacity(ScsiReq *rp, int argc, char **argv)
 {
-	return capacity(rp, 10);
+	uchar d[32];
+	long n, r;
+	uvlong i;
+
+	if((r = SRrcapacity(rp, d)) == -1)
+		return -1;
+	i = GETBELONG(d);
+	if(i == 0xffffffff)
+		return capacity16(rp, argc, argv);
+	n = GETBELONG(d + 4);
+	Bprint(&bout, " %llud %lud\n", i, n);
+	return r;
 }
 
 static long
-cmdcapacity16(ScsiReq *rp, int, char **)
+cmdcapacity16(ScsiReq *rp, int argc, char **argv)
 {
-	return capacity(rp, 16);
+	return capacity16(rp, argc, argv);
 }
 
 static char* mamattr[] = {