9boot: list known filesystem images on usb stick as boot filesystems

rc/bin/nusbrc

@@ -25,6 +25,7 @@ if(! bind -a '#u' /dev)
 		}
 	}
 	fn detach {
+		# handled /sys/src/9/boot/nusbrc
 	}
 	rc < '#σ/usb/usbevent' &
 }

sys/src/9/boot/local.rc

@@ -2,8 +2,7 @@
 
 fn showlocaldevs{
 	echo local devices found:
-	for(d in /dev/sd*){
-		if(test -r $d/ctl){
+	for(d in /dev/sd*) if(test -r $d/ctl){
 		q=`{sed 's,(inquiry|geometry),\
 \1,g' $d/ctl | grep inquiry}
 		echo $d':' $q(2-)
@@ -22,6 +21,16 @@ fn showlocaldevs{
 			}
 		}
 	}
+	for(d in /shr/sd*) if(test -d $d) {
+		echo $d':'
+		for(p in $d/*.^(iso kfs paq)) if(test -f $p){
+			t=`{fstype $p}
+			if(! ~ $t ''){
+				if(~ $#bootargs 0)
+					bootargs=local!$p
+				echo $p $t
+			}
+		}
 	}
 }
 
@@ -34,7 +43,7 @@ fn bootfs{
 }
 
 fn connectlocal{
-	if(test -r $1)
+	if(test -f $1)
 		t=`{fstype $1}
 	if not {
 		t=$1; shift
@@ -44,22 +53,10 @@ fn connectlocal{
 		fatal unknown fstype $1
 	case 9660
 		bootfs 9660srv $*
+	case dos
+		bootfs dossrv $*
 	case kfs
 		bootfs disk/kfs $*
-	case dos
-		if(! test -f /srv/dos)
-			dossrv
-		m=/mnt/dosboot
-		must mount /srv/dos $m $1
-		shift
-		if(~ $#* 0)
-			f=$m/9front.iso
-		if not
-			f=$m/$1
-		if(test -r $f)
-			connectlocal $f
-		if not
-			connectlocal $*
 	case *
 		bootfs $t $*
 	}

sys/src/9/boot/nusbrc

@@ -17,18 +17,15 @@ if(! nusb/usbd)
 			@{
 				rfork ne
 				cd '#σ/usb'
-				for(dev in sdU^$1.*){
-					echo $dev...
+				for(dev in sdU^$1.*) if(test -d $dev) {
 					diskparts $dev
-					for(part in $dev/dos* $dev/9fat){
-						if(test -r $part) {
-							mkdir -m 0700 '#σc/'^$dev
+					for(part in $dev/dos* $dev/9fat) if(test -r $part) {
+						mkdir -m 0700 '#σc/'^$dev || exit
 						{dossrv -s -f $part &} <[0=1] |
 							echo 0 >'#σc/'^$dev/dos
 						exit
 					}
 				}
-				}
 			} &
 		}
 	}