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: []
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); 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.