LED failed attempt, GPIO working

rootfs_overlay/README.md

@@ -6,3 +6,7 @@ We use it to for things like:
 
 - customized configuration files
 - userland module test scripts
+
+Most tests correspond clearly to a given kernel module, but the following ones don't, e.g. they correspond to mainline tree features:
+
+- [gpio](gpio.sh)

rootfs_overlay/gpio.sh

@@ -0,0 +1,27 @@
+#!/bin/sh
+set -e
+cd /sys/class/gpio
+echo 480 > export
+echo 481 > export
+echo 482 > export
+echo 488 > export
+echo 496 > export
+echo out > gpio480/direction
+echo out > gpio481/direction
+echo out > gpio482/direction
+echo out > gpio488/direction
+echo out > gpio496/direction
+v=1
+while true; do
+  echo $v > gpio480/value
+  echo $v > gpio481/value
+  echo $v > gpio482/value
+  echo $v > gpio488/value
+  echo $v > gpio496/value
+  if [ $v -eq 1 ]; then
+    v=0
+  else
+    v=1
+  fi
+  sleep 1
+done