Gowin IDE patcher

patch.py

#!/usr/bin/python3

import os
import re
import subprocess
import mmap

def patch(filename : str, bytes):
    subprocess.run(["cp",filename, filename + '_patched'])
    with open(filename + "_patched", "r+b") as f:
        mm = mmap.mmap(f.fileno(), 0)
        location = mm.find(bytes)
        print("  found at offset: ", location, "len = ", len(bytes), "bytes")

        patchbytes = bytearray([0x90] * len(bytes)) # NOP
        patchbytes[0] = 0x30 # XOR %al %al
        patchbytes[1] = 0xC0
        patchbytes[2] = 0xFE # INC %al
        patchbytes[3] = 0xC0
        mm[location:location+len(bytes)] = patchbytes
        mm.close()

files = os.listdir(os.getcwd())

# remove all non-executables and directories
files = [filename for filename in files if os.access(filename, os.X_OK) == True]
files = [filename for filename in files if os.path.isdir(filename) == False]

# 
files = [filename for filename in files if filename.endswith(tuple([".json", ".ini", ".v", ".xml", ".conf", ".py","_backup", ".vhd"])) == False]

functionName = "_ZN4GLIC15checkoutLicenseEPKc"
reHexByte = "([0-9a-fA-F]{2})"
hexBytes  = re.compile(reHexByte)

for filename in files:
    print("Processing: ", filename)
    result = subprocess.run(["objdump", "--disassemble=main", filename], capture_output=True, text=True, check=True)

    if functionName in result.stdout:
        print("  patching.. ")

        for line in result.stdout.split("\n"):
            if (functionName in line):
                print(line)
                sline = line.split("\t")
                if (len(sline) <2):
                    print("Cannot find bytes!")
                else:
                    bytematch = hexBytes.findall(sline[1])
                    if (len(bytematch) >= 5):
                        print("Found bytes: ", sline[1])
                        searchBytes = bytes([int(x,16) for x in bytematch])
                        patch(filename, searchBytes)