src/snagrecover/protocols/rockchip.py: Add rockchip maskrom support

Add support for uploading blods to the maskrom memory using Rockchip
maskrom protocol.

Signed-off-by: Arnaud Patard <[email protected]>

Author: apatard

src/snagrecover/protocols/rockchip.py

@@ -0,0 +1,91 @@
+# Copyright 2025 Collabora Ltd.
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Author: Arnaud Patard <[email protected]>
+
+
+from crccheck.crc import Crc16Ibm3740
+import logging
+import usb
+
+from snagrecover import utils
+
+logger = logging.getLogger("snagrecover")
+
+
+class RochipBootRomError(Exception):
+	pass
+
+class RochipBootRom():
+	def __init__(self, dev: usb.core.Device):
+		self.dev = dev
+		cfg = dev.get_active_configuration()
+
+		eps_found = False
+		for intf in cfg.interfaces():
+			ep_in, ep_out = None, None
+			for ep in intf.endpoints():
+				is_bulk = (ep.bmAttributes & usb.ENDPOINT_TYPE_MASK) == usb.ENDPOINT_TYPE_BULK
+				is_in = (ep.bmAttributes & usb.ENDPOINT_TYPE_MASK) == usb.ENDPOINT_TYPE_BULK
+				if not is_bulk:
+					continue
+				is_in = (ep.bEndpointAddress & usb.ENDPOINT_DIR_MASK) == usb.ENDPOINT_IN
+				if is_in:
+					ep_in = ep.bEndpointAddress
+				else:
+					ep_out = ep.bEndpointAddress
+			if not ((ep_in is None) or (ep_out is None)):
+				eps_found = True
+				break
+		if not eps_found:
+			raise RochipBootRomError("No BULK IN/OUT endpoint pair found in device")
+		self.ep_in = ep_in
+		self.ep_out = ep_out
+
+	def __write_chunk(self, addr: int, chunk: bytes) -> bool:
+		logger.debug(f"Sending {len(chunk)} bytes")
+		return self.dev.ctrl_transfer(0x40, 0x0c, 0, addr, chunk)
+
+	def write_blob(self, blob: bytes, addr: int) -> bool:
+		if addr != 0x471 and addr != 0x472:
+			raise RochipBootRomError("Invalid address. Can only be 471 or 472")
+		crc = Crc16Ibm3740()
+		total_written = 0
+		crc_sent = False
+		for chunk in utils.dnload_iter(blob, 4096):
+			chunk_len = len(chunk)
+			if chunk_len == 4096:
+				crc.process(chunk)
+			elif chunk_len == 4095:
+				chunk.append(0x00)
+				crc.process(chunk)
+			else:
+				crc.process(chunk)
+				crcbytes = crc.final()
+				chunk = bytearray(chunk)
+				chunk.append(crcbytes >> 8)
+				chunk.append(crcbytes & 0xff)
+				crc_sent = True
+			written = self.__write_chunk(addr, chunk)
+			ret = written == len(chunk)
+			if ret is False:
+				return ret
+			total_written += written
+			if chunk_len+2 == 4096:
+				chunk = [0x00]
+				written = self.__write_chunk(addr, chunk)
+				ret = written == len(chunk)
+				if ret is False:
+					return ret
+		if crc_sent is False:
+			chunk = bytearray()
+			crcbytes = crc.final()
+			chunk.append(crcbytes >> 8)
+			chunk.append(crcbytes & 0xff)
+			written = self.__write_chunk(addr, chunk)
+			ret = written == len(chunk)
+			if ret is False:
+				return ret
+
+		return True