MarlinFirmware/buildroot/share/PlatformIO/scripts/lerdge.py

#
# lerdge.py
# Customizations for Lerdge build environments:
#   env:LERDGEX  env:LERDGEX_usb_flash_drive
#   env:LERDGES  env:LERDGES_usb_flash_drive
#   env:LERDGEK  env:LERDGEK_usb_flash_drive
#
import pioutil
if pioutil.is_pio_build():
	import os,marlin
	Import("env")

	from SCons.Script import DefaultEnvironment
	board = DefaultEnvironment().BoardConfig()

	def encryptByte(byte):
		byte = 0xFF & ((byte << 6) | (byte >> 2))
		i = 0x58 + byte
		j = 0x05 + byte + (i >> 8)
		byte = (0xF8 & i) | (0x07 & j)
		return byte

	def encrypt_file(input, output_file, file_length):
		input_file = bytearray(input.read())
		for i in range(len(input_file)):
			input_file[i] = encryptByte(input_file[i])
		output_file.write(input_file)

	# Encrypt ${PROGNAME}.bin and save it with the name given in build.encrypt
	def encrypt(source, target, env):
		fwpath = target[0].path
		enname = board.get("build.encrypt")
		print("Encrypting %s to %s" % (fwpath, enname))
		fwfile = open(fwpath, "rb")
		enfile = open(target[0].dir.path + "/" + enname, "wb")
		length = os.path.getsize(fwpath)

		encrypt_file(fwfile, enfile, length)

		fwfile.close()
		enfile.close()
		os.remove(fwpath)

	if 'encrypt' in board.get("build").keys():
		if board.get("build.encrypt") != "":
			marlin.add_post_action(encrypt)
	else:
		print("LERDGE builds require output file via board_build.encrypt = 'filename' parameter")
		exit(1)