#!/bin/sh

usage()
{
  echo "Usage: $0 <milliseconds>" >&2
  echo "  Returns zero if the reset button is held for >= millseconds." >&2
  exit 9
}

[ "$#" = 1 ] || usage
[ "$1" -gt 1 ] || usage


# wait until gpio-mailbox has had at least one loop
wait-until-created /tmp/gpio/ready

retval=1  # not pressed
while [ -e /tmp/gpio/reset_button_msecs ]; do
  # reset button is pressed at boot time; wait to see if the user
  # holds it for $1 msec
  usleep 100000
  if [ -e /tmp/gpio/reset_button_msecs ]; then
    msecs=
    read msecs </tmp/gpio/reset_button_msecs
    echo "reset button held for $msecs msecs so far"
    if [ "$msecs" -gt "$1" ]; then
      retval=0  # pressed for long enough
      break
    fi
  fi
done

exit $retval