old_contents: from subprocess import call
  import os
  import shutil
  import glob
  
  def compile():
      print("Compiling DTS Files")
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-spi2.dtbo", "-b", "o", "-@", "overlays/chip-spi2.dts"])
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-i2c1.dtbo", "-b", "o", "-@", "overlays/chip-i2c1.dts"])
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-pwm0.dtbo", "-b", "o", "-@", "overlays/chip-pwm0.dts"])
  
  def copy():
      print("Checking for DTBO Install Path")
      if not os.path.exists("/lib/firmware/chip_io/"):
          print("Path not found, creating /lib/firmware/chip_io/")
          os.makedirs("/lib/firmware/chip_io/")
      print("Removing old DTBO files (if applicable)")
      for fl in glob.glob("/lib/firmware/chip_io/chip-*-.dtbo"):
          os.remove(fl)
      print("Moving DTBO files to /lib/firmware/chip_io/")
      shutil.move("overlays/chip-spi2.dtbo", "/lib/firmware/chip_io/chip-spi2.dtbo")
      shutil.move("overlays/chip-i2c1.dtbo", "/lib/firmware/chip_io/chip-i2c1.dtbo")
      shutil.move("overlays/chip-pwm0.dtbo", "/lib/firmware/chip_io/chip-pwm0.dtbo")
  
  
new_contents: from subprocess import call
  import os
  import shutil
  import glob
  import sys
  
  def compile():
      print("Compiling DTS Files")
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-spi2.dtbo", "-b", "o", "-@", "overlays/chip-spi2.dts"])
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-i2c1.dtbo", "-b", "o", "-@", "overlays/chip-i2c1.dts"])
      call(["dtc", "-O", "dtb", "-o", "overlays/chip-pwm0.dtbo", "-b", "o", "-@", "overlays/chip-pwm0.dts"])
  
  def copy():
      target_dir = os.environ.get('TARGET_DIR', '')
      overlay_path = target_dir + "/lib/firmware/chip_io"
      print("Checking for DTBO Install Path")
      if not os.path.exists(overlay_path):
          print("Path not found, creating "+overlay_path)
          os.makedirs(overlay_path)
      print("Removing old DTBO files (if applicable)")
      for fl in glob.glob(overlay_path+"/chip-*-.dtbo"):
          os.remove(fl)
      print("Moving DTBO files to "+overlay_path)
      shutil.move("overlays/chip-spi2.dtbo", overlay_path+"/chip-spi2.dtbo")
      shutil.move("overlays/chip-i2c1.dtbo", overlay_path+"/chip-i2c1.dtbo")
      shutil.move("overlays/chip-pwm0.dtbo", overlay_path+"/chip-pwm0.dtbo")
  
subject: Add 'TARGET_DIR' prefix env var to builder.py