Actual working Binary Ninja NDS plugin

nds.py

# Copyright (c) 2015-2024 Vector 35 Inc
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

from binaryninja import *

import struct
import traceback

def crc16(data):
	crc = 0xffff
	for ch in data:
		crc ^= ch
		for bit in range(0, 8):
			if (crc & 1) == 1:
				crc = (crc >> 1) ^ 0xa001
			else:
				crc >>= 1
	return crc


class DSView(BinaryView):
	name = "NDS"
	long_name = "Nintendo DS"
	
	def __init__(self, parent):
		BinaryView.__init__(self, file_metadata = parent.file, parent_view = parent)
		self.raw = parent

	@staticmethod
	def is_valid_for_data(data):
		hdr = data.read(0, 0x160)
		if len(hdr) < 0x160:
			return False
		if struct.unpack("<H", hdr[0x15e:0x160])[0] != crc16(hdr[0:0x15e]):
			print("CRC check failed, are you sure your header/ROM is valid?")
			return False
		if struct.unpack("<H", hdr[0x15c:0x15e])[0] != crc16(hdr[0xc0:0x15c]):
			print("CRC check failed, are you sure your header/ROM is valid?")
			return False
		return True

	def init_common(self):
		self.arch = Architecture["armv7"]
		self.platform = Architecture["armv7"].standalone_platform  # type: ignore
		self.hdr = self.raw.read(0, 0x160)

	def init_arm9(self):
		try:
			self.init_common()
			self.arm9_offset = struct.unpack("<L", self.hdr[0x20:0x24])[0]
			self.arm9_entry_addr = struct.unpack("<L", self.hdr[0x24:0x28])[0]
			self.arm9_load_addr = struct.unpack("<L", self.hdr[0x28:0x2C])[0]
			self.arm9_size = struct.unpack("<L", self.hdr[0x2C:0x30])[0]
			self.add_auto_segment(
			  self.arm9_load_addr, self.arm9_size, self.arm9_offset, self.arm9_size,
			  SegmentFlag.SegmentReadable | SegmentFlag.SegmentExecutable
			)
			self.add_entry_point(self.arm9_entry_addr)
			self.add_function(self.arm9_entry_addr)
			self.define_auto_symbol(Symbol(SymbolType.FunctionSymbol, self.arm9_entry_addr, "_start9"))
			return True
		except:
			log_error(traceback.format_exc())
			return False

	def init_arm7(self):
		try:
			self.init_common()
			self.arm7_offset = struct.unpack("<L", self.hdr[0x30:0x34])[0]
			self.arm7_entry_addr = struct.unpack("<L", self.hdr[0x34:0x38])[0]
			self.arm7_load_addr = struct.unpack("<L", self.hdr[0x38:0x3C])[0]
			self.arm7_size = struct.unpack("<L", self.hdr[0x3C:0x40])[0]
			self.add_auto_segment(
			  self.arm7_load_addr, self.arm7_size, self.arm7_offset, self.arm7_size,
			  SegmentFlag.SegmentReadable | SegmentFlag.SegmentExecutable
			)
			self.add_entry_point(self.arm7_entry_addr)  # type: ignore
			self.add_function(self.arm7_entry_addr)
			self.define_auto_symbol(Symbol(SymbolType.FunctionSymbol, self.arm7_entry_addr, "_start7"))

			return True
		except:
			log_error(traceback.format_exc())
			return False

	def perform_is_executable(self):
		return True

	def perform_get_entry_point(self):
		return self.arm9_entry_addr
	
	def perform_get_address_size(self):
		return 4
	
	def init(self):
		return self.init_arm9() and self.init_arm7()

DSView.register()