destogod/re/find_const.py
type-two 07977624ae DestoGod: replacement for the TP5 bus destination sign software
TP5 is a 2012 Windows application supplied with the Guangzhou-Tongda LED
destination signs fitted to Yutong buses. It has no preview, so building a
destination list is guess-and-check, and it only runs on Windows.

The bus never talks to TP5 — the sign controller reads a .td5 file off an SD
card, and that is the whole interface. So this replaces the software without
touching any hardware or protocol: it just has to write byte-correct .td5.

Formats reverse-engineered from the sample files and TP5(En).exe, then verified
byte-for-byte:

  .td5   the file the bus reads. Fixed-layout binary; each destination block
         carries a CRC-16/ARC over block[3..len] and a rand() block id, which
         together looked like one 4-byte field because RAND_MAX is 0x7fff.
  .tp5   the editable project. Line-based text, UTF-16BE hex strings.
  .font  the sign's own bitmap fonts, each glyph row XORed with its char code.

The app is one self-contained HTML file: live LED preview at the real sign size
with real scrolling, spreadsheet/CSV import, multi-page destinations, undoable
delete, and export to both .td5 and .tp5.

Verified:
  - rebuilds a real 46,080-byte TP5 export byte-for-byte with a recomputed CRC
  - all 36 stored CRCs verify against the implementation
  - driven through its own UI, re-exporting the real file differs in 7 bytes,
    all of them the export timestamp
  - running on a real bus: signs and driver's controller both correct

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-21 13:06:25 +10:00

15 lines
700 B
Python

import re
d = open('/Users/jing/Documents/yutong/yutongapp/TP5(En).exe','rb').read()
def hits(pat, lo=0x1000, hi=0x46000):
return [m.start() for m in re.finditer(re.escape(pat), d[lo:hi])]
for name,pat in [('0x11684', b'\x84\x16\x01\x00'), ('0x11684 push', b'\x68\x84\x16\x01\x00')]:
h = hits(pat)
print(name, [hex(x+0x1000) for x in h])
print('--- MSVCRT imports ---')
import pefile
p = pefile.PE('/Users/jing/Documents/yutong/yutongapp/TP5(En).exe')
for e in p.DIRECTORY_ENTRY_IMPORT:
if b'MSVCRT' in e.dll.upper() or b'KERNEL32' in e.dll.upper():
for imp in e.imports:
print(e.dll.decode(), '%08x' % imp.address, imp.name.decode() if imp.name else imp.ordinal)