ktemkin · April 29, 2023 07:03
diff --git a/roli_fw_extract.py b/roli_fw_extract.py
 #!/usr/bin/python3

 import math

 import mido

 FIRMWARE_IN = "firmware.syx"
 FIRMWARE_OUT = "firmware.bin"

 FIRMWARE_PUSH_COMMAND = 0x04

 leftover_data = []


 def demangle(data):
    """ Demangles data that's been encoded as 7-bit numbers. """

    input_data  = data[:]
    output_data = bytearray()


    while input_data:
        chunk = input_data[0:8]
        del input_data[0:8]

        # Typically, we get 7 bytes per 8, since we had 7 of 8 bits...
        resultant_size = math.floor(len(chunk) * 7 / 8)
        resultant_bits = resultant_size * 8

        # Convert the 7-bit chunks into one fewer eight bit chunks...
        septets         = [f"{i:07b}" for i in chunk]
        long_equivalent = "".join(septets)[0:resultant_bits]

        # ... and convert that back to bytes.
        raw = int(long_equivalent, 2)
        octets = raw.to_bytes(resultant_size, byteorder='big')

        output_data.extend(octets)


    print(len(output_data))
    return output_data


 # Read the firware into memory.
 roli_syx = mido.read_syx_file(FIRMWARE_IN)

 # Prepare to write our output file.
 output = open(FIRMWARE_OUT, "wb")


 # Go through each message, and see what we have.
 for message in roli_syx:
    data = list(message.data)

    # The first byte is already extracted for us, as it's SysEx standard.
    # The next four bytes are ID information and separator; throw those away.
    del data[0:4]

    # The _last_ byte is a checksum of the packet.
    # Discard it.
    del data[-1]

    # The next byte is the command.
    command = data.pop(0)

    # Skip non-firmware commands.
    if command not in [FIRMWARE_PUSH_COMMAND]:
        continue

    data_demangled = demangle(data)
    
    address = data_demangled[0:4]
    address = int.from_bytes(address, byteorder='little')
    del data_demangled[0:4]

    output.write(data_demangled)
	#!/usr/bin/python3

	import math

	import mido

	FIRMWARE_IN = "firmware.syx"
	FIRMWARE_OUT = "firmware.bin"

	FIRMWARE_PUSH_COMMAND = 0x04

	leftover_data = []


	def demangle(data):
	""" Demangles data that's been encoded as 7-bit numbers. """

	input_data = data[:]
	output_data = bytearray()


	while input_data:
	chunk = input_data[0:8]
	del input_data[0:8]

	# Typically, we get 7 bytes per 8, since we had 7 of 8 bits...
	resultant_size = math.floor(len(chunk) * 7 / 8)
	resultant_bits = resultant_size * 8

	# Convert the 7-bit chunks into one fewer eight bit chunks...
	septets = [f"{i:07b}" for i in chunk]
	long_equivalent = "".join(septets)[0:resultant_bits]

	# ... and convert that back to bytes.
	raw = int(long_equivalent, 2)
	octets = raw.to_bytes(resultant_size, byteorder='big')

	output_data.extend(octets)


	print(len(output_data))
	return output_data


	# Read the firware into memory.
	roli_syx = mido.read_syx_file(FIRMWARE_IN)

	# Prepare to write our output file.
	output = open(FIRMWARE_OUT, "wb")


	# Go through each message, and see what we have.
	for message in roli_syx:
	data = list(message.data)

	# The first byte is already extracted for us, as it's SysEx standard.
	# The next four bytes are ID information and separator; throw those away.
	del data[0:4]

	# The _last_ byte is a checksum of the packet.
	# Discard it.
	del data[-1]

	# The next byte is the command.
	command = data.pop(0)

	# Skip non-firmware commands.
	if command not in [FIRMWARE_PUSH_COMMAND]:
	continue

	data_demangled = demangle(data)

	address = data_demangled[0:4]
	address = int.from_bytes(address, byteorder='little')
	del data_demangled[0:4]

	output.write(data_demangled)