diff -r 287d82efe5f2 sys/src/9/boot/bootrc
--- a/sys/src/9/boot/bootrc	Mon Jan 13 23:22:35 2020 +0000
+++ b/sys/src/9/boot/bootrc	Sat Jan 18 17:00:51 2020 +0100
@@ -43,6 +43,21 @@
 	$* || fatal $"*^': '^$status
 }
 
+fn wait_timeout {
+	@{
+	echo waiting $1 seconds for $*(2-)
+	seconds=$1
+	shift
+	while (test $seconds -gt 0) {
+		if ($*)
+			exit ''
+		seconds=`{echo $seconds | awk '{print($1-1)}'}
+		sleep 1
+	}
+	exit timeout
+	}
+}
+
 fn ask {
 	echo -n $1
 	echo -n $2
@@ -65,6 +80,11 @@
 mt=()
 
 fn main{
+	echo nobootprompt is $"nobootprompt
+	waitfor=(300 test -d /dev/sdUc420e/)
+	if (! ~ $#waitfor 0) {
+		wait_timeout $waitfor || echo $status
+	}
 	mp=()
 	while(~ $#mp 0){
 		if(~ $#nobootprompt 0){
@@ -185,7 +205,7 @@
 
 # add partitions and binds
 configlocal
-
+nobootprompt='local!/dev/sdUc420e/fs'
 while(){
 	@{main}