boot(8): use first detected filesystem as bootargs default

sys/lib/dist/pc/plan9.ini.cd

@@ -1,13 +1,7 @@
 # config for initial cd booting
-# very cautious settings to get started.
-# will defeat booting from usb devices.
 *nodumpstack=1
-partition=new
 mouseport=ask
 monitor=ask
 vgasize=ask
 cdboot=yes
-# console=0
-# baud=9600
-bootargs=local!#S/sdD0/data
 bootfile=/386/9pcf

sys/src/9/boot/local.rc

@@ -6,9 +6,13 @@ fn showlocaldevs{
 		if(test -r $c){
 			d=`{echo $c | sed 's,/ctl,,g'}
 			echo $d':' `{sed 's/inquiry[ ]+//g; q' $c}
-			for(i in `{ls -p $d | grep -v -e 'ctl|raw'})
-				echo $d'/'$i `{fstype $d'/'$i}
-			echo
+			for(i in `{ls -p $d | grep -v -e 'ctl|raw'}){
+				p=$d/$i
+				t=`{fstype $p}
+				if(~ $#bootargs 0 && ! ~ $t '')
+					bootargs=local!$p
+				echo $p $t
+			}
 		}
 	}
 }