Ensures the basic RPi firmware is in the given folder

rpi_firmware

#!/bin/sh
FIRMWAREURL="https://raw.githubusercontent.com/raspberrypi/firmware/master/boot/"

DIR="$1"
[ ! -d "${DIR}" ] && { echo "First argument should be a directory that exists"; exit 1; }
for firmware in LICENCE.broadcom bootcode.bin fixup.dat start.elf; do
  firmware_dest="${DIR}/${firmware}";
  if [ ! -f "${firmware_dest}" ]; then
    echo "Downloading RPi firmware: ${firmware}";
    curl --silent --output "${firmware_dest}" "${FIRMWAREURL}${firmware}";
  fi;
done
echo "RPi firmware present"