havoc-remaster/tools/find_string.py
pyr0ball 27174a1c79 feat: NOCD patch boots Havoc on modern Windows (defeats CD copy protection)
Diagnosed and fixed the crash that killed HAVOC_NOCD.EXE ~1s after launch
(dgVoodoo window appears black, then the process exits). It was not a clean
exit: an ACCESS_VIOLATION (null-pointer read at VA 0x444E6A) during init.

Root cause is a copy-protection check in the WORLDS\ data-file loader
(0x42a480). It opens each file (GRAFIX/LAND/MAP/STUF) from both a local
"WORLDS\<name>" path and a CD-drive path (HAVOC.INI [SETUP] DRIVE=D:\), and
returns a valid stream only when the local open fails and the CD-drive open
succeeds. With files present locally and no D: drive it returned NULL, and the
GRAFIX loader (0x444db0) dereferenced that NULL without checking.

Fix: 14-byte patch at FO 0x29a2b rewrites the return decision to hand back the
successfully-opened local object. The game now boots to the title screen
("HAVOC(tm) by Reality Bytes"), responsive, main loop running.

- docs/PATCHES.md: full patch table (28 patches) + crash write-up
- tools/: RE + patching scripts (r2pipe disasm, minidump parser, ctypes
  debugger, PE/IAT/import analysis)
- run_probe.bat / run_and_log.bat: reliable native launch for repro
- .gitignore: exclude CD images, Ghidra install/project, dgVoodoo, *.ini

Diagnosed via WER minidumps (%LOCALAPPDATA%\CrashDumps) parsed in pure Python
(no cdb/windbg available).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TN4Ytn3gdWRonNmHpisWQv
2026-07-03 09:29:59 -07:00

20 lines
820 B
Python

import struct, sys, io
sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
data = open('HAVOC_NOCD.EXE','rb').read()
FO2VA = lambda fo: fo + 0x400C00
# Search for "corrupted" and "unavailable" strings
for needle in [b'corrupt', b'unavail', b'CORRUPT', b'UNAVAIL', b'not found', b'NOT FOUND',
b'cannot', b'CANNOT', b'missing', b'MISSING', b'invalid', b'INVALID']:
idx = 0
while True:
pos = data.find(needle, idx)
if pos == -1: break
# Print surrounding context
start = max(0, pos - 4)
end = min(len(data), pos + 60)
snippet = data[start:end]
printable = ''.join(chr(b) if 32 <= b < 127 else '.' for b in snippet)
print("FO 0x%05x VA 0x%08x: %s" % (pos, FO2VA(pos), printable))
idx = pos + 1