diff --git a/scripts/autoupdate-usb.sh b/scripts/autoupdate-usb.sh
old mode 100644
new mode 100755
index b112008..bb2e0ae
--- a/scripts/autoupdate-usb.sh
+++ b/scripts/autoupdate-usb.sh
@@ -1,13 +1,15 @@
 #!/bin/sh
+SHELLDIR=$(cd `dirname $0`; pwd)
+echo "shell dir $SHELLDIR"
 
 cd /mnt/mmcblk0p2
 rm -rf artifact R2S*.zip FriendlyWrt*img*
-cp $(dirname $(readlink -f $0))/R2S-Minimal-$(date +%Y-%m-%d)-ROM.zip ./
+cp $SHELLDIR/R2S-Minimal-$(date +%Y-%m-%d)-ROM.zip ./
 if [ -f /mnt/mmcblk0p2/R2S*.zip ]; then
 	echo -e '\e[92m今天固件已下载，准备解压\e[0m'
 else
 	echo -e '\e[91m今天的固件还没更新，尝试下载昨天的固件\e[0m'
-	cp $(dirname $(readlink -f $0))/R2S-Minimal-$(date -d "@$(( $(busybox date +%s) - 86400))" +%Y-%m-%d)-ROM.zip ./
+	cp $SHELLDIR/R2S-Minimal-$(date -d "@$(( $(busybox date +%s) - 86400))" +%Y-%m-%d)-ROM.zip ./
 	if [ -f /mnt/mmcblk0p2/R2S*.zip ]; then
 		echo -e '\e[92m昨天的固件已下载，准备解压\e[0m'
 	else