diff --git a/buildroot b/buildroot
index e39044f..cf3ea90 160000
--- a/buildroot
+++ b/buildroot
@@ -1 +1 @@
-Subproject commit e39044fa44394042e22f503fb53ba96122956bce
+Subproject commit cf3ea901082f470449bd174272d8407e039522b2
diff --git a/os-buildroot/override/root/blink.sh b/os-buildroot/override/root/blink.sh
new file mode 100755
index 0000000..4435b53
--- /dev/null
+++ b/os-buildroot/override/root/blink.sh
@@ -0,0 +1,112 @@
+#!/bin/sh
+set -u
+
+VERBOSE=0
+PIN=""
+SLEEP=1
+GPIOS=""
+
+while getopts "hvr:p:s:" OPT; do
+    case "$OPT" in
+    h)
+        echo "Usage:   blink.sh [-hv] [-r PIN_RANGE_FROM-PIN_RANGE_TO] [-p PIN] [-s SLEEP_SEC]"
+        echo "Example: blink.sh -r 0-10 -p 12"
+        echo "         (blink from GPIO 0 to 10 and 12)"
+        exit 0
+        ;;
+    v)
+        VERBOSE=1
+        ;;
+    r)
+        RE='^([0-9]+)-([0-9]+)$'
+        if echo $OPTARG | grep -qvE $RE; then
+            echo "Error: invalid range: $OPTARG"
+            exit 1
+        fi
+        FROM=$(echo $OPTARG | sed -E "s/$RE/\\1/")
+        TO=$(echo $OPTARG | sed -E "s/$RE/\\2/")
+        GPIOS="$GPIOS$(seq -s " " $FROM $TO) "
+        ;;
+    p)
+        if echo $OPTARG | grep -qvE "^[0-9]+$"; then
+            echo "Error: invalid pin number: $OPTARG"
+            exit 1
+        fi
+        GPIOS="$GPIOS$OPTARG "
+        ;;
+    s)
+        if echo $OPTARG | grep -qvE "^[0-9]+$"; then
+            echo "Error: invalid sleep duration: $OPTARG"
+            exit 1
+        fi
+        SLEEP=$OPTARG
+        ;;
+    esac
+done
+
+if [ $VERBOSE -eq 1 ]; then
+    echo "Pins to iterate over: $GPIOS"
+fi
+
+if [ "$(id -u)" -ne "0" ]; then
+    echo "Error: please run as root"
+    exit 1
+fi
+
+AVAILABLE_GPIOS=""
+
+export_gpio() {
+    echo $1 > /sys/class/gpio/export
+}
+
+set_direction() {
+    echo out > /sys/class/gpio/gpio$1/direction
+}
+
+set_value() {
+    echo $2 > /sys/class/gpio/gpio$1/value
+}
+
+for i in $GPIOS; do
+    if [ ! -e "/sys/class/gpio/gpio$i" ]; then
+        export_gpio $i 2>/dev/null
+        if [ $? -ne 0 ]; then
+            echo "Error: failed to export the pin $i"
+            continue
+        fi
+    fi
+
+    set_direction $i 2>/dev/null
+    if [ $? -ne 0 ]; then
+        # Ignore the failure if the actual direction is out
+        if grep -vq "out" /dsys/class/gpio/gpio$i/direction; then
+            echo "Error: failed to set the direction of the pin $i to out"
+            continue
+        fi
+    fi
+
+    AVAILABLE_GPIOS="$AVAILABLE_GPIOS$i "
+done
+
+echo "Available GPIOs: $AVAILABLE_GPIOS"
+
+while [ 1 ]; do
+    for i in $AVAILABLE_GPIOS; do
+        set_value $i 1 2>/dev/null
+        if [ $? -ne 0 ]; then
+            echo "Warning: failed to set the value of the pin $i to high"
+        fi
+    done
+
+    sleep $SLEEP
+
+    for i in $AVAILABLE_GPIOS; do
+        set_value $i 0 2>/dev/null
+        if [ $? -ne 0 ]; then
+            echo "Warning: failed to set the value of the pin $i to low"
+        fi
+    done
+
+    sleep $SLEEP
+done
+