emulator: Sonic 1 & 2 (2013) Decompilation
type: standalone
core_classification: game_engine
source: "https://github.com/RSDKModding/RSDKv4-Decompilation"
upstream: "https://github.com/RSDKModding/RSDKv4-Decompilation"
source_commit: "a7f5195e21fdad7b75e4587e249013feeea9e6f3"
core_version: "1.3.3"
profiled_date: "2026-10-04"
display_name: "Sonic 1 & 2 (2013) (RSDKv4 Decomp)"
cores: [sonicretro]
systems: [sonic-1-2013, sonic-2-2013]

notes: |
  Shared Retro Engine v4 decompilation driving the 2013 Christian Whitehead
  mobile ports of Sonic the Hedgehog and Sonic the Hedgehog 2. One binary
  per build. The game identity is derived from the GameConfig.bin inside
  the loaded data pack (gameWindowText "Sonic 1" or "Sonic 2").
  ref: RSDKv4/RetroEngine.cpp:423, RSDKv4/ModAPI.cpp:428

  CheckRSDKFile opens the data pack and compares its first six bytes to
  the "RSDKvB" signature. There is no checksum test. The engine falls
  back to a loose Data/ + Bytecode/ tree if the pack is absent. When
  GameConfig.bin cannot be loaded either way it writes a usage.txt that
  asks for a pack named Engine.dataFile[0] (default "Data.rsdk").
  ref: RSDKv4/Reader.cpp:25-102, RSDKv4/RetroEngine.cpp:296-331,
       RSDKv4/Userdata.cpp:251-263, RSDKv4/RetroEngine.cpp:483-520

  Up to four packs can be mounted (DataFile, DataFile2..4 in the Dev
  section of settings.ini), and the extras default to Data2.rsdk, Data3.rsdk,
  Data4.rsdk once declared.
  ref: RSDKv4/Reader.hpp:38, RSDKv4/RetroEngine.cpp:324-331,
       RSDKv4/Userdata.cpp:396-408

files:
  - name: "Data.rsdk"
    category: game_data
    system: sonic-1-2013
    required: true
    source_ref: "RSDKv4/Userdata.cpp:251-252 (default name), RSDKv4/Userdata.cpp:396-397 (Dev:DataFile), RSDKv4/RetroEngine.cpp:316-321 (CheckRSDKFile call), RSDKv4/Reader.cpp:38-46 (signature check)"
    note: |
      Sonic the Hedgehog (2013) assets. Shipped with the official Sonic
      Origins release and the delisted iOS/Android apps. The engine checks
      the six-byte signature only. Content identity is read from the
      embedded GameConfig.bin, not the pack hash.

  - name: "Data.rsdk"
    category: game_data
    system: sonic-2-2013
    required: true
    source_ref: "RSDKv4/Userdata.cpp:251-252 (default name), RSDKv4/Userdata.cpp:396-397 (Dev:DataFile), RSDKv4/RetroEngine.cpp:316-321 (CheckRSDKFile call), RSDKv4/Reader.cpp:38-46 (signature check)"
    note: |
      Sonic the Hedgehog 2 (2013) assets. Shipped with the official Sonic
      Origins release and the delisted iOS/Android apps. Same default
      file name as Sonic 1. Dev:DataFile in settings.ini names another.