xenia-rs

Rust reimplementation of the Xbox 360 emulator xenia, focused on reverse-engineering and preservation rather than full-speed play. The initial target is Project Sylpheed — Arc of Deception; getting the title disassembled, traced, and far enough into its init path to understand its engine.

Heavy cross-reference to xenia-canary for CPU context setup, kernel export behavior, and XEX loading semantics.

Status

• XEX loader — XEX2 header parsing, LZX decompression, AES decryption, PE section parsing.
• VFS / XISO — XGD2 dual-layer disc images (with the 0x0FD90000 partition offset).
• PPC interpreter — 200+ opcodes, PowerPC 32/64-bit GPR/FPR, VMX128 decoding.
• Static analyzer — function discovery (prolog/epilog heuristics), cross-references, labels, save/restore helper detection, assembly text + SQLite database output.
• Kernel HLE — minimal subset driving Project Sylpheed: ~170 xboxkrnl + xam exports (critical sections, events, TLS, virtual memory, Vd stubs, XAM input/user/content).
• Debugger — in-memory step/break, SQLite execution + import-call + branch tracing.

Not yet: GPU (xenos/xe-shader), APU audio, HID, kernel scheduler, full threading, exception delivery.

Workspace

crates/
  xenia-types       # shared primitive types, bitflags
  xenia-memory      # guest memory, paged allocator, page table
  xenia-cpu         # PPC decoder, interpreter, context
  xenia-xex         # XEX2 loader, PE parser, LZX, AES
  xenia-vfs         # XISO / disc-image reader
  xenia-kernel      # HLE kernel state, exports, XAM
  xenia-gpu         # (stub) Xenos command processor
  xenia-apu         # (stub) XAudio
  xenia-hid         # (stub) XInput
  xenia-debugger    # in-memory trace, breakpoints, step modes
  xenia-analysis    # function/xref analysis, assembly formatter, SQLite DbWriter
  xenia-app         # `xenia-rs` CLI binary

CLI

Build:

cargo build --release

The binary xenia-rs accepts XEX2 files or ISO / XISO disc images as input (the loader auto-detects discs and extracts default.xex).

info / browse / disasm

Quick header / disc / first-N-instructions inspection. See --help.

extract — unpack PE + metadata

xenia-rs extract <xex-or-iso> [-o <out-dir>] [--db <sqlite-path>]

Writes <name>.pe (decompressed/decrypted PE image) and <name>.xex.json (header metadata). With --db, also emits a SQLite database containing the base tables: metadata, sections, imports.

dis — full disassembly

xenia-rs dis <xex-or-iso> [-o <asm-file>] [--db <sqlite-path>] [--quiet]

Runs function + cross-reference analysis and produces:

• assembly text to stdout or -o <file> (unless --quiet)
• optional SQLite DB with the base tables + disasm tables: functions, labels, instructions, xrefs

exec — interpret with tracing

xenia-rs exec <xex-or-iso> [-n <max-instrs>] [--db <sqlite-path>]
             [--trace-instructions] [--trace-imports] [--trace-branches]

Loads the title, initializes CPU state per xenia-canary, intercepts import thunks with HLE kernel calls, and interprets from the entry point. Without -n, runs until halt/fault. With --db, produces a DB that is a superset of dis --db plus opt-in trace tables:

flag	table	rows
--trace-instructions	exec_trace	one row per interpreted instruction (PC, r3/r4, LR, SP)
--trace-imports	import_calls	one row per kernel/XAM call (module, ordinal, args)
--trace-branches	branch_trace	taken branches classified as call/return/jump/branch

Cumulative DB layering

Each command's DB is a superset of the previous. A single xenia-rs exec <iso> --db full.db --trace-instructions --trace-imports --trace-branches produces the full picture in one pass — base tables, complete static disassembly, and runtime traces correlatable by address/cycle.

Performance knobs

• XENIA_DB_BATCH_SIZE — rows per streaming commit / trace-buffer flush (default 100_000). Lower values reduce memory use; higher values reduce fsync overhead on slow disks.

The DB writer uses journal_mode=OFF, synchronous=OFF, locking_mode=EXCLUSIVE and commits in batches; no ANALYZE is run at finalize. Indices are created after bulk insertion with progress messages.

Example queries

-- Top 20 kernel functions called during early init
SELECT name, COUNT(*) FROM import_calls GROUP BY name ORDER BY 2 DESC LIMIT 20;

-- All basic-block leaders (targets of taken branches) not already labelled
SELECT DISTINCT bt.target
FROM branch_trace bt LEFT JOIN labels l ON l.address = bt.target
WHERE l.address IS NULL;

-- Correlate a traced call site with its static disassembly
SELECT et.cycle, i.disasm, i.ext_disasm
FROM exec_trace et JOIN instructions i ON i.address = et.address
WHERE et.address = 0x824AB748 ORDER BY et.cycle;

License

BSD-3-Clause, matching upstream xenia.