Watch Dogs Wii U — RPX Binary & Symbol Table

Source: duniademo.rpx from Watch Dogs (USA) Wii U retail disc Extracted via JWUDTool with USA WUD key 5a5b5fef63fade1603497770fa43a394

RPX Binary Format

Field	Value
File	duniademo.rpx (51,080,768 bytes)
Format	ELF32 big-endian, Cafe OS (ABI 0xCA)
Type	0xFE01 (Cafe OS executable)
Machine	0x0014 (Cafe OS PowerPC)
Entry point	0x06E67A08
Build path	F:\master\code\duniademo.rpx
Sections	36 ELF section headers

Cafe OS Section Types

Cafe OS extends ELF with custom section types:

Type ID	Name	Purpose
0x80000001	CAFE_PROLOG	Function prolog data
0x80000002	CAFE_EXIDX	Exception handling index
0x80000003	CAFE_UNWIND	Stack unwinding info
0x80000004	CAFE_EXTAB	Exception table

Symbol Table

The RPX contains a massive symbol table -- 317,063 symbols with full mangled C++ names. This is unusual for a retail build; the Wii U version retained symbols that were stripped from PS4, Xbox 360, and PC retail releases.

Compression

Both SYMTAB and STRTAB are zlib-compressed with a 4-byte header:

Offset Size Description
0x00 4 Header (skip this)
0x04 var zlib deflate data

Decompression (Python):

import zlib
with open('duniademo.rpx', 'rb') as f:
 f.seek(offset) # SYMTAB: 0x1C5180, STRTAB: 0x3D5BC0
 raw = f.read(size) # SYMTAB: 0x210A35, STRTAB: 0x366AE2
 data = zlib.decompress(raw[4:]) # Skip 4-byte header

Section Layout

Section	Index	Offset	Size (compressed)	Size (decompressed)
SYMTAB	31	0x1C5180	2,165,301 bytes	5,073,008 bytes
STRTAB	32	0x3D5BC0	3,566,242 bytes	31,036,367 bytes
SH strtab	33	0x73C6C0	167 bytes	167 bytes (uncompressed)

Symbol Counts

Type	Count
FUNC	317,019
OBJECT	11
SECTION	32
NOTYPE	1
Total	317,063

Bind	Count
LOCAL	110,040
GLOBAL	135,633
WEAK	71,389

Symbol Format

Each symbol entry is 16 bytes (ELF32_Sym, big-endian):

Offset Size Field
0x00 4 st_name (index into STRTAB)
0x04 4 st_value (virtual address)
0x08 4 st_size (symbol size in bytes)
0x0C 1 st_info (bind << 4 | type)
0x0D 1 st_other (visibility)
0x0E 2 st_shndx (section index)

st_info encoding: bind = st_info >> 4, type = st_info & 0xF

Symbol types: NOTYPE(0), OBJECT(1), FUNC(2), SECTION(3), FILE(4) Symbol binds: LOCAL(0), GLOBAL(1), WEAK(2)

Notable Symbol Categories

Category	Count	Examples
Game engine	~500+	SEngineParameters, CDuniaEngineInitBase
BehaviorTree tasks	~155+	BTCallRegisterNodeCTask, RegisterProperties
Sound (SND)	~107+	SND_fn_b*, SND_fn_v*
XML parsing	~42+	XmlNodeRef, XmlConstNodeRef, XML_DefaultAllocator
Ref counting	~58+	CRefCounted, CRefCountWith
Threading	~30+	CMessageQueue, CTaskSynchLock, Gear::ThreadBase
Bink video	~28+	Bink* functions
Memory	~29+	MemHelper, MEMAllocFromDefaultHeap
Archive	1+	CCryArchiveManagerNative
Expat XML	~80+	normal_*, utf8_*, little2_*, big2_* encoding functions

Why This Matters

The PC, PS4, and Xbox 360 retail builds of Watch Dogs have their symbol tables completely stripped. The Wii U retail build retained the full SYMTAB/STRTAB, making it the best source for reverse engineering the Disrupt engine's C++ class hierarchy.

No DWARF debug sections (.debug_*) are present -- Cafe OS uses SYMTAB/STRTAB as its sole symbol mechanism. The symbol table IS the debug info.

Parser Script

The Python parser used to extract these symbols is at: rpx_parse_v2.py

Full symbol CSV (317,063 rows) at: rpx_symbols.csv

Extraction Steps

1. Obtain USA WUD key: 5a5b5fef63fade1603497770fa43a394
2. Decrypt .wux with JWUDTool (or equivalent WUD decryptor)
3. Locate GM0005000010142000000000000000/code/duniademo.rpx
4. Parse ELF32 header (big-endian, 52 bytes)
5. Read 36 section headers at offset 0x40 (40 bytes each)
6. Decompress SYMTAB (section 31) and STRTAB (section 32) with zlib
7. Parse ELF32_Sym entries (16 bytes each) from decompressed SYMTAB
8. Resolve names from decompressed STRTAB